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<!--Created on: 2/21/2018 11:28:26 AM-->
<!--Modified on: 2/21/2018 11:28:26 AM-->
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures_lbl" xml:lang="en-US">Carrying Amount</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRentReceivablesNet" xlink:to="us-gaap_DeferredRentReceivablesNet_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredRentReceivablesNet_lbl" xml:lang="en-US">Unbilled rents receivable, net</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherAssets" xlink:label="us-gaap_OtherAssets" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssets" xlink:to="us-gaap_OtherAssets_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherAssets_lbl" xml:lang="en-US">Other Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OtherAssets_lbl" xml:lang="en-US">Total deferred charges, goodwill and other assets, net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OtherAssets_lbl" xml:lang="en-US">Deferred charges, goodwill and other assets, net</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalents" xlink:label="us-gaap_RestrictedCashAndCashEquivalents" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedCashAndCashEquivalents" xlink:to="us-gaap_RestrictedCashAndCashEquivalents_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RestrictedCashAndCashEquivalents_lbl" xml:lang="en-US">Restricted Cash And Cash Equivalents</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_RestrictedCashAndCashEquivalents_lbl" xml:lang="en-US">Total restricted cash</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_RestrictedCashAndCashEquivalents_lbl" xml:lang="en-US">Restricted cash</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountsReceivableNet" xlink:label="us-gaap_AccountsReceivableNet" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivableNet" xlink:to="us-gaap_AccountsReceivableNet_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsReceivableNet_lbl" xml:lang="en-US">Accounts Receivable Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccountsReceivableNet_lbl" xml:lang="en-US">Accounts receivable, net of allowance for doubtful accounts of $1,138 and $1,335</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Assets_lbl" xml:lang="en-US">Total assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Assets_lbl" xml:lang="en-US">Total assets</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xml:lang="en-US">LIABILITIES AND EQUITY</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SeniorNotes" xlink:label="us-gaap_SeniorNotes" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SeniorNotes" xlink:to="us-gaap_SeniorNotes_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SeniorNotes_lbl" xml:lang="en-US">Senior Notes</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SeniorNotes_lbl" xml:lang="en-US">Senior unsecured notes, net</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCredit" xlink:label="us-gaap_LineOfCredit" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCredit" xlink:to="us-gaap_LineOfCredit_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCredit_lbl" xml:lang="en-US">Revolving credit facility</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:label="us-gaap_LineOfCredit_lbl" xml:lang="en-US">Unsecured revolving credit facility and term loans</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCredit_lbl" xml:lang="en-US">Amount outstanding</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LineOfCredit_lbl" xml:lang="en-US">Outstanding borrowings under the facility</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SecuredDebt" xlink:label="us-gaap_SecuredDebt" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SecuredDebt" xlink:to="us-gaap_SecuredDebt_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SecuredDebt_lbl" xml:lang="en-US">Secured Debt</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SecuredDebt_lbl" xml:lang="en-US">Mortgages, loans payable and other obligations, net</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DividendsPayableCurrentAndNoncurrent" xlink:label="us-gaap_DividendsPayableCurrentAndNoncurrent" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendsPayableCurrentAndNoncurrent" xlink:to="us-gaap_DividendsPayableCurrentAndNoncurrent_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DividendsPayableCurrentAndNoncurrent_lbl" xml:lang="en-US">Dividends and distributions payable</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent" xlink:to="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent_lbl" xml:lang="en-US">Accounts payable, accrued expenses and other liabilities</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RentsReceivedInAdvanceAndSecurityDeposits" xlink:label="cli_RentsReceivedInAdvanceAndSecurityDeposits" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RentsReceivedInAdvanceAndSecurityDeposits" xlink:to="cli_RentsReceivedInAdvanceAndSecurityDeposits_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RentsReceivedInAdvanceAndSecurityDeposits_lbl" xml:lang="en-US">Amount at the balance sheet date including both: (a) rents and other amounts paid in advance by tenants and clients; and (b) security deposits paid in advance to protect the provider of a service, such as a lessor, against damage or nonpayment by the tenant (lessee) during the term of the agreement.  Such damages may include physical damage to the property, theft of property, and other contractual breaches.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RentsReceivedInAdvanceAndSecurityDeposits_lbl" xml:lang="en-US">Rents received in advance and security deposits</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InterestPayableCurrentAndNoncurrent" xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPayableCurrentAndNoncurrent" xlink:to="us-gaap_InterestPayableCurrentAndNoncurrent_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent_lbl" xml:lang="en-US">Accrued interest payable</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Liabilities_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Liabilities_lbl" xml:lang="en-US">Total liabilities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Liabilities_lbl" xml:lang="en-US">Total liabilities</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="us-gaap_CommitmentsAndContingencies" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingencies" xlink:to="us-gaap_CommitmentsAndContingencies_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingencies_lbl" xml:lang="en-US">Commitments And Contingencies 2009</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommitmentsAndContingencies_lbl" xml:lang="en-US">Commitments and contingencies</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RedeemableNoncontrollingInterestEquityFairValue" xlink:label="us-gaap_RedeemableNoncontrollingInterestEquityFairValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RedeemableNoncontrollingInterestEquityFairValue" xlink:to="us-gaap_RedeemableNoncontrollingInterestEquityFairValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RedeemableNoncontrollingInterestEquityFairValue_lbl" xml:lang="en-US">Redeemable Noncontrolling Interest, Equity, Fair Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_RedeemableNoncontrollingInterestEquityFairValue_lbl" xml:lang="en-US">Redeemable noncontrolling interests as of December 31, 2017</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_RedeemableNoncontrollingInterestEquityFairValue_lbl" xml:lang="en-US">Balance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RedeemableNoncontrollingInterestEquityFairValue_lbl" xml:lang="en-US">Redeemable noncontrolling interests</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_lbl" xml:lang="en-US">Equity:</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="us-gaap_StockholdersEquityAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_StockholdersEquityAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xml:lang="en-US">Stockholders' Equity Attributable to Parent [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xml:lang="en-US">Mack-Cali Realty stockholders' equity:</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValue" xlink:to="us-gaap_CommonStockValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockValue_lbl" xml:lang="en-US">Common stock value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CommonStockValue_lbl" xml:lang="en-US">Common stock, $0.01 par value, 190,000,000 shares authorized, 89,914,113 and 89,696,713 shares outstanding</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapital" xlink:to="us-gaap_AdditionalPaidInCapital_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdditionalPaidInCapital_lbl" xml:lang="en-US">Additional Paid In Capital</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AdditionalPaidInCapital_lbl" xml:lang="en-US">Additional paid-in capital</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GeneralPartnersCapitalAccount" xlink:label="us-gaap_GeneralPartnersCapitalAccount" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GeneralPartnersCapitalAccount" xlink:to="us-gaap_GeneralPartnersCapitalAccount_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GeneralPartnersCapitalAccount_lbl" xml:lang="en-US">General Partners' Capital Account</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_GeneralPartnersCapitalAccount_lbl" xml:lang="en-US">General Partner, 89,914,113 and 89,696,713 common units outstanding</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LimitedPartnersCapitalAccount" xlink:label="us-gaap_LimitedPartnersCapitalAccount" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LimitedPartnersCapitalAccount" xlink:to="us-gaap_LimitedPartnersCapitalAccount_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LimitedPartnersCapitalAccount_lbl" xml:lang="en-US">Limited Partners' Capital Account</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LimitedPartnersCapitalAccount_lbl" xml:lang="en-US">Limited partners, 10,438,855 and 10,488,105 common units outstanding</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xml:lang="en-US">Retained Earnings Accumulated Deficit</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xml:lang="en-US">Dividends in excess of net earnings</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xml:lang="en-US">Accumulated Other Comprehensive Income (Loss), Net of Tax</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xml:lang="en-US">Accumulated other comprehensive income (loss)</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US">Stockholders' Equity Attributable to Parent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US">Total Mack-Cali Realty Corporation stockholders' equity</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PartnersCapital" xlink:label="us-gaap_PartnersCapital" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PartnersCapital" xlink:to="us-gaap_PartnersCapital_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PartnersCapital_lbl" xml:lang="en-US">Partners' Capital</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PartnersCapital_lbl" xml:lang="en-US">Total Mack-Cali Realty, L.P. partners' capital</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NoncontrollingInterestItemsAbstract" xlink:label="us-gaap_NoncontrollingInterestItemsAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncontrollingInterestItemsAbstract" xlink:to="us-gaap_NoncontrollingInterestItemsAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NoncontrollingInterestItemsAbstract_lbl" xml:lang="en-US">Noncontrolling Interest Items [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_NoncontrollingInterestItemsAbstract_lbl" xml:lang="en-US">Noncontrolling interests in subsidiaries:</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinorityInterestInOperatingPartnerships" xlink:label="us-gaap_MinorityInterestInOperatingPartnerships" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinorityInterestInOperatingPartnerships" xlink:to="us-gaap_MinorityInterestInOperatingPartnerships_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MinorityInterestInOperatingPartnerships_lbl" xml:lang="en-US">Operating Partnership</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinorityInterestInJointVentures" xlink:label="us-gaap_MinorityInterestInJointVentures" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinorityInterestInJointVentures" xlink:to="us-gaap_MinorityInterestInJointVentures_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MinorityInterestInJointVentures_lbl" xml:lang="en-US">Minority Interest In Joint Ventures</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MinorityInterestInJointVentures_lbl" xml:lang="en-US">Consolidated joint ventures</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinorityInterest" xlink:label="us-gaap_MinorityInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinorityInterest" xlink:to="us-gaap_MinorityInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MinorityInterest_lbl" xml:lang="en-US">Total noncontrolling interests in subsidiaries</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_MinorityInterest_lbl" xml:lang="en-US">Total noncontrolling interests in subsidiaries</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US">Total equity</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US">Balance, value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US">Balance, value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US">Total equity</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PartnersCapitalAttributableToNoncontrollingInterest" xlink:label="us-gaap_PartnersCapitalAttributableToNoncontrollingInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PartnersCapitalAttributableToNoncontrollingInterest" xlink:to="us-gaap_PartnersCapitalAttributableToNoncontrollingInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PartnersCapitalAttributableToNoncontrollingInterest_lbl" xml:lang="en-US">Partners' Capital Attributable to Noncontrolling Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PartnersCapitalAttributableToNoncontrollingInterest_lbl" xml:lang="en-US">Noncontrolling interests in consolidated joint ventures</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest" xlink:label="us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest" xlink:to="us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US">Partners' Capital, Including Portion Attributable to Noncontrolling Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US">Balance, value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US">Balance, value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US">Total equity</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xml:lang="en-US">Liabilities And Stockholders Equity</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xml:lang="en-US">Total liabilities and equity</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl" xml:lang="en-US">Allowance for doubtful accounts receivable</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl" xml:lang="en-US">Allowance for doubtful accounts receivable</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockParOrStatedValuePerShare" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xml:lang="en-US">Common stock, par value per share</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesAuthorized" xlink:to="us-gaap_CommonStockSharesAuthorized_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xml:lang="en-US">Common stock, shares authorized</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesOutstanding" xlink:to="us-gaap_CommonStockSharesOutstanding_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xml:lang="en-US">Common Stock Shares Outstanding</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xml:lang="en-US">Common stock, shares outstanding</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GeneralPartnersCapitalAccountUnitsOutstanding" xlink:label="us-gaap_GeneralPartnersCapitalAccountUnitsOutstanding" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GeneralPartnersCapitalAccountUnitsOutstanding" xlink:to="us-gaap_GeneralPartnersCapitalAccountUnitsOutstanding_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GeneralPartnersCapitalAccountUnitsOutstanding_lbl" xml:lang="en-US">General Partners' Capital Account, Units Outstanding</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_GeneralPartnersCapitalAccountUnitsOutstanding_lbl" xml:lang="en-US">General partner common units outstanding</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LimitedPartnersCapitalAccountUnitsOutstanding" xlink:label="us-gaap_LimitedPartnersCapitalAccountUnitsOutstanding" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LimitedPartnersCapitalAccountUnitsOutstanding" xlink:to="us-gaap_LimitedPartnersCapitalAccountUnitsOutstanding_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LimitedPartnersCapitalAccountUnitsOutstanding_lbl" xml:lang="en-US">Limited Partners' Capital Account, Units Outstanding</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LimitedPartnersCapitalAccountUnitsOutstanding_lbl" xml:lang="en-US">Limited partner common units outstanding</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeStatementAbstract" xlink:label="us-gaap_IncomeStatementAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeStatementAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeStatementAbstract_lbl" xml:lang="en-US">Consolidated Statements Of Operations [Abstract]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenuesAbstract" xlink:label="us-gaap_RevenuesAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenuesAbstract" xlink:to="us-gaap_RevenuesAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenuesAbstract_lbl" xml:lang="en-US">Revenues Abstract</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RevenuesAbstract_lbl" xml:lang="en-US">REVENUES</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesIncomeStatementLeaseRevenue" xlink:label="us-gaap_OperatingLeasesIncomeStatementLeaseRevenue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesIncomeStatementLeaseRevenue" xlink:to="us-gaap_OperatingLeasesIncomeStatementLeaseRevenue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesIncomeStatementLeaseRevenue_lbl" xml:lang="en-US">Operating Leases, Income Statement, Lease Revenue</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeasesIncomeStatementLeaseRevenue_lbl" xml:lang="en-US">Lease revenue</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesIncomeStatementLeaseRevenue_lbl" xml:lang="en-US">Base rents</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TenantReimbursements" xlink:label="us-gaap_TenantReimbursements" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TenantReimbursements" xlink:to="us-gaap_TenantReimbursements_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TenantReimbursements_lbl" xml:lang="en-US">Escalations and recoveries from tenants</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherRealEstateRevenue" xlink:label="us-gaap_OtherRealEstateRevenue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherRealEstateRevenue" xlink:to="us-gaap_OtherRealEstateRevenue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherRealEstateRevenue_lbl" xml:lang="en-US">Other Real Estate Revenue</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherRealEstateRevenue_lbl" xml:lang="en-US">Real estate services</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ParkingRevenue" xlink:label="us-gaap_ParkingRevenue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ParkingRevenue" xlink:to="us-gaap_ParkingRevenue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ParkingRevenue_lbl" xml:lang="en-US">Parking Revenue</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ParkingRevenue_lbl" xml:lang="en-US">Parking income</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherOperatingIncome" xlink:label="us-gaap_OtherOperatingIncome" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherOperatingIncome" xlink:to="us-gaap_OtherOperatingIncome_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherOperatingIncome_lbl" xml:lang="en-US">Other income</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateRevenueNet" xlink:label="us-gaap_RealEstateRevenueNet" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateRevenueNet" xlink:to="us-gaap_RealEstateRevenueNet_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateRevenueNet_lbl" xml:lang="en-US">Real Estate Revenue, Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RealEstateRevenueNet_lbl" xml:lang="en-US">Total revenues</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_RealEstateRevenueNet_lbl" xml:lang="en-US">Total revenues</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CostOfRevenueAbstract" xlink:label="us-gaap_CostOfRevenueAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostOfRevenueAbstract" xlink:to="us-gaap_CostOfRevenueAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CostOfRevenueAbstract_lbl" xml:lang="en-US">EXPENSES</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateTaxExpense" xlink:label="us-gaap_RealEstateTaxExpense" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateTaxExpense" xlink:to="us-gaap_RealEstateTaxExpense_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateTaxExpense_lbl" xml:lang="en-US">Real estate taxes</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UtilitiesCosts" xlink:label="us-gaap_UtilitiesCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UtilitiesCosts" xlink:to="us-gaap_UtilitiesCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UtilitiesCosts_lbl" xml:lang="en-US">Utilities</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingCostsAndExpenses" xlink:label="us-gaap_OperatingCostsAndExpenses" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingCostsAndExpenses" xlink:to="us-gaap_OperatingCostsAndExpenses_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingCostsAndExpenses_lbl" xml:lang="en-US">Operating services</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CostsOfRealEstateServices" xlink:label="cli_CostsOfRealEstateServices" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CostsOfRealEstateServices" xlink:to="cli_CostsOfRealEstateServices_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CostsOfRealEstateServices_lbl" xml:lang="en-US">The aggregate costs including administrative paperwork, real estate brokerage, title, and property management operations.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CostsOfRealEstateServices_lbl" xml:lang="en-US">Costs Of Real Estate Services</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_CostsOfRealEstateServices_lbl" xml:lang="en-US">Real estate services expenses</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="us-gaap_GeneralAndAdministrativeExpense" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GeneralAndAdministrativeExpense" xlink:to="us-gaap_GeneralAndAdministrativeExpense_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GeneralAndAdministrativeExpense_lbl" xml:lang="en-US">General and administrative</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AcquisitionRelatedCosts" xlink:label="cli_AcquisitionRelatedCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AcquisitionRelatedCosts" xlink:to="cli_AcquisitionRelatedCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AcquisitionRelatedCosts_lbl" xml:lang="en-US">Costs associated with acquiring new properties.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AcquisitionRelatedCosts_lbl" xml:lang="en-US">Acquisition-Related Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AcquisitionRelatedCosts_lbl" xml:lang="en-US">Acquisition-related costs</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DepreciationAndAmortization" xlink:label="us-gaap_DepreciationAndAmortization" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationAndAmortization" xlink:to="us-gaap_DepreciationAndAmortization_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DepreciationAndAmortization_lbl" xml:lang="en-US">Depreciation and amortization</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DepreciationAndAmortization_lbl" xml:lang="en-US">Depreciation and amortization</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AssetImpairmentCharges" xlink:label="us-gaap_AssetImpairmentCharges" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetImpairmentCharges" xlink:to="us-gaap_AssetImpairmentCharges_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetImpairmentCharges_lbl" xml:lang="en-US">Impairment charge</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_AssetImpairmentCharges_lbl" xml:lang="en-US">Impairments</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetImpairmentCharges_lbl" xml:lang="en-US">Impairments</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CostsAndExpenses" xlink:label="us-gaap_CostsAndExpenses" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostsAndExpenses" xlink:to="us-gaap_CostsAndExpenses_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CostsAndExpenses_lbl" xml:lang="en-US">Costs and Expenses</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CostsAndExpenses_lbl" xml:lang="en-US">Total expenses</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingIncomeLoss_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xml:lang="en-US">Operating income</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xml:lang="en-US">Operating income (loss)</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NonoperatingIncomeExpenseAbstract" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xml:lang="en-US">OTHER (EXPENSE) INCOME</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InterestExpense" xlink:label="us-gaap_InterestExpense" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpense" xlink:to="us-gaap_InterestExpense_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestExpense_lbl" xml:lang="en-US">Interest expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_InterestExpense_lbl" xml:lang="en-US">Interest expense</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_InvestmentIncomeLossNonoperating" xlink:label="cli_InvestmentIncomeLossNonoperating" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_InvestmentIncomeLossNonoperating" xlink:to="cli_InvestmentIncomeLossNonoperating_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_InvestmentIncomeLossNonoperating_lbl" xml:lang="en-US">Investment Income (Loss), Nonoperating</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_InvestmentIncomeLossNonoperating_lbl" xml:lang="en-US">Investment Income (Loss), Nonoperating</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_InvestmentIncomeLossNonoperating_lbl" xml:lang="en-US">Interest and other investment income (loss)</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeLossFromEquityMethodInvestments" xlink:label="us-gaap_IncomeLossFromEquityMethodInvestments" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromEquityMethodInvestments" xlink:to="us-gaap_IncomeLossFromEquityMethodInvestments_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossFromEquityMethodInvestments_lbl" xml:lang="en-US">Equity in earnings (loss) of unconsolidated joint ventures</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncomeLossFromEquityMethodInvestments_lbl" xml:lang="en-US">Equity in (earnings) loss of unconsolidated joint ventures</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:label="us-gaap_IncomeLossFromEquityMethodInvestments_lbl" xml:lang="en-US">Equity in earnings (loss) of unconsolidated joint ventures</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeLossFromEquityMethodInvestments_lbl" xml:lang="en-US">Company's equity in earnings of unconsolidated joint ventures</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_GainLossOnChangeOfControlOfInterests" xlink:label="cli_GainLossOnChangeOfControlOfInterests" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_GainLossOnChangeOfControlOfInterests" xlink:to="cli_GainLossOnChangeOfControlOfInterests_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_GainLossOnChangeOfControlOfInterests_lbl" xml:lang="en-US">Gain (Loss) On Change Of Control Of Interests</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_GainLossOnChangeOfControlOfInterests_lbl" xml:lang="en-US">Gain (Loss) On Change Of Control Of Interests</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_GainLossOnChangeOfControlOfInterests_lbl" xml:lang="en-US">Gain on change of control of interests</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_GainLossOnChangeOfControlOfInterests_lbl" xml:lang="en-US">Gain on change of control of interests</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GainLossOnDispositionOfAssets" xlink:label="us-gaap_GainLossOnDispositionOfAssets" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnDispositionOfAssets" xlink:to="us-gaap_GainLossOnDispositionOfAssets_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GainLossOnDispositionOfAssets_lbl" xml:lang="en-US">Realized gains on disposition of rental property</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_GainLossOnDispositionOfAssets_lbl" xml:lang="en-US">Realized gains (losses) and unrealized losses on disposition of rental property, net</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GainLossOnSaleOfInvestments" xlink:label="us-gaap_GainLossOnSaleOfInvestments" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnSaleOfInvestments" xlink:to="us-gaap_GainLossOnSaleOfInvestments_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GainLossOnSaleOfInvestments_lbl" xml:lang="en-US">Gain (Loss) on Sale of Investments</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_GainLossOnSaleOfInvestments_lbl" xml:lang="en-US">Gain on sale of investments in unconsolidated joint ventures</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_GainLossOnSaleOfInvestments_lbl" xml:lang="en-US">Gain (loss) on sale of investment in unconsolidated joint venture</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_GainLossOnSaleOfInvestments_lbl" xml:lang="en-US">Gain on sale of investment in unconsolidated joint venture</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ExtinguishmentOfDebtGainLossNetOfTax" xlink:label="us-gaap_ExtinguishmentOfDebtGainLossNetOfTax" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ExtinguishmentOfDebtGainLossNetOfTax" xlink:to="us-gaap_ExtinguishmentOfDebtGainLossNetOfTax_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ExtinguishmentOfDebtGainLossNetOfTax_lbl" xml:lang="en-US">Extinguishment of Debt, Gain (Loss), Net of Tax</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ExtinguishmentOfDebtGainLossNetOfTax_lbl" xml:lang="en-US">Loss from extinguishment of debt, net</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NonoperatingIncomeExpenseIncludingEquityMethodInvestments" xlink:label="cli_NonoperatingIncomeExpenseIncludingEquityMethodInvestments" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NonoperatingIncomeExpenseIncludingEquityMethodInvestments" xlink:to="cli_NonoperatingIncomeExpenseIncludingEquityMethodInvestments_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NonoperatingIncomeExpenseIncludingEquityMethodInvestments_lbl" xml:lang="en-US">Nonoperating Income Expense Including Equity Method Investments</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NonoperatingIncomeExpenseIncludingEquityMethodInvestments_lbl" xml:lang="en-US">Nonoperating Income Expense Including Equity Method Investments</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_NonoperatingIncomeExpenseIncludingEquityMethodInvestments_lbl" xml:lang="en-US">Total other income (expense)</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProfitLoss" xlink:label="us-gaap_ProfitLoss" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProfitLoss" xlink:to="us-gaap_ProfitLoss_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProfitLoss_lbl" xml:lang="en-US">Net income</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProfitLoss_lbl" xml:lang="en-US">Net income (loss)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_ProfitLoss_lbl" xml:lang="en-US">Net income (loss)</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NoncontrollingInterestInNetIncomeLossJointVenturePartnersNonredeemable" xlink:label="us-gaap_NoncontrollingInterestInNetIncomeLossJointVenturePartnersNonredeemable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncontrollingInterestInNetIncomeLossJointVenturePartnersNonredeemable" xlink:to="us-gaap_NoncontrollingInterestInNetIncomeLossJointVenturePartnersNonredeemable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NoncontrollingInterestInNetIncomeLossJointVenturePartnersNonredeemable_lbl" xml:lang="en-US">Noncontrolling interest in consolidated joint ventures</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_NoncontrollingInterestInNetIncomeLossJointVenturePartnersNonredeemable_lbl" xml:lang="en-US">Add: Noncontrolling interest in consolidated joint ventures</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:label="us-gaap_NoncontrollingInterestInNetIncomeLossJointVenturePartnersNonredeemable_lbl" xml:lang="en-US">Noncontrolling interest in consolidated joint ventures</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NoncontrollingInterestInNetIncomeLossOperatingPartnershipsNonredeemable" xlink:label="us-gaap_NoncontrollingInterestInNetIncomeLossOperatingPartnershipsNonredeemable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncontrollingInterestInNetIncomeLossOperatingPartnershipsNonredeemable" xlink:to="us-gaap_NoncontrollingInterestInNetIncomeLossOperatingPartnershipsNonredeemable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NoncontrollingInterestInNetIncomeLossOperatingPartnershipsNonredeemable_lbl" xml:lang="en-US">Noncontrolling interest in operating partnership</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_NoncontrollingInterestInNetIncomeLossOperatingPartnershipsNonredeemable_lbl" xml:lang="en-US">Noncontrolling interest in Operating Partnership</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:label="us-gaap_NoncontrollingInterestInNetIncomeLossOperatingPartnershipsNonredeemable_lbl" xml:lang="en-US">Add (deduct): Noncontrolling interest in Operating Partnership</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NoncontrollingInterestInNetIncomeLossOperatingPartnershipsNonredeemable_lbl" xml:lang="en-US">Add (deduct): Noncontrolling interest in Operating Partnership</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest" xlink:label="us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest" xlink:to="us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest_lbl" xml:lang="en-US">Net Income (Loss) Attributable to Redeemable Noncontrolling Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest_lbl" xml:lang="en-US">Redeemable noncontrolling interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:label="us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest_lbl" xml:lang="en-US">Income Attributed to Noncontrolling Interests</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_lbl" />
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharesOutstanding" xlink:label="us-gaap_SharesOutstanding" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesOutstanding" xlink:to="us-gaap_SharesOutstanding_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharesOutstanding_lbl" xml:lang="en-US">Shares, Issued</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_SharesOutstanding_lbl" xml:lang="en-US">Balance, shares</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_SharesOutstanding_lbl" xml:lang="en-US">Balance, shares</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PartnersCapitalAccountUnits" xlink:label="us-gaap_PartnersCapitalAccountUnits" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PartnersCapitalAccountUnits" xlink:to="us-gaap_PartnersCapitalAccountUnits_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PartnersCapitalAccountUnits_lbl" xml:lang="en-US">Partners' Capital Account, Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_PartnersCapitalAccountUnits_lbl" xml:lang="en-US">Balance, units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_PartnersCapitalAccountUnits_lbl" xml:lang="en-US">Balance, units</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest" xlink:label="us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest" xlink:to="us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_lbl" xml:lang="en-US">Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_lbl" xml:lang="en-US">Net income (loss)</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DividendsCommonStock" xlink:label="us-gaap_DividendsCommonStock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendsCommonStock" xlink:to="us-gaap_DividendsCommonStock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DividendsCommonStock_lbl" xml:lang="en-US">Common stock dividends</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DividendsCommonStock_lbl" xml:lang="en-US">Common stock dividends</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:label="us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:to="us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_lbl" xml:lang="en-US">Common unit distributions</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_lbl" xml:lang="en-US">Common unit distributions</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NoncontrollingInterestIncreaseFromSaleOfParentEquityInterest" xlink:label="us-gaap_NoncontrollingInterestIncreaseFromSaleOfParentEquityInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncontrollingInterestIncreaseFromSaleOfParentEquityInterest" xlink:to="us-gaap_NoncontrollingInterestIncreaseFromSaleOfParentEquityInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NoncontrollingInterestIncreaseFromSaleOfParentEquityInterest_lbl" xml:lang="en-US">Noncontrolling Interest, Increase from Sale of Parent Equity Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NoncontrollingInterestIncreaseFromSaleOfParentEquityInterest_lbl" xml:lang="en-US">Issuance of limited partner common units, value</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NoncontrollingInterestSharesIncreaseFromSaleOfParentEquityInterest" xlink:label="cli_NoncontrollingInterestSharesIncreaseFromSaleOfParentEquityInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NoncontrollingInterestSharesIncreaseFromSaleOfParentEquityInterest" xlink:to="cli_NoncontrollingInterestSharesIncreaseFromSaleOfParentEquityInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NoncontrollingInterestSharesIncreaseFromSaleOfParentEquityInterest_lbl" xml:lang="en-US">Noncontrolling Interest, Shares, Increase from Sale of Parent Equity Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NoncontrollingInterestSharesIncreaseFromSaleOfParentEquityInterest_lbl" xml:lang="en-US">Noncontrolling Interest, Shares, Increase from Sale of Parent Equity Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NoncontrollingInterestSharesIncreaseFromSaleOfParentEquityInterest_lbl" xml:lang="en-US">Issuance of limited partner common units, shares</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RedeemableNoncontrollingInterestRedemptionValueAdjustment" xlink:label="cli_RedeemableNoncontrollingInterestRedemptionValueAdjustment" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RedeemableNoncontrollingInterestRedemptionValueAdjustment" xlink:to="cli_RedeemableNoncontrollingInterestRedemptionValueAdjustment_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RedeemableNoncontrollingInterestRedemptionValueAdjustment_lbl" xml:lang="en-US">Redeemable Noncontrolling Interest Redemption Value Adjustment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RedeemableNoncontrollingInterestRedemptionValueAdjustment_lbl" xml:lang="en-US">Redeemable Noncontrolling Interest Redemption Value Adjustment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RedeemableNoncontrollingInterestRedemptionValueAdjustment_lbl" xml:lang="en-US">Redemption Value Adjustment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_RedeemableNoncontrollingInterestRedemptionValueAdjustment_lbl" xml:lang="en-US">Redeemable noncontrolling interest</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinorityInterestPeriodIncreaseDecrease" xlink:label="us-gaap_MinorityInterestPeriodIncreaseDecrease" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinorityInterestPeriodIncreaseDecrease" xlink:to="us-gaap_MinorityInterestPeriodIncreaseDecrease_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MinorityInterestPeriodIncreaseDecrease_lbl" xml:lang="en-US">Noncontrolling Interest, Period Increase (Decrease)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MinorityInterestPeriodIncreaseDecrease_lbl" xml:lang="en-US">Increase (Decrease) in noncontrolling interest in consolidated joint ventures</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MinorityInterestIncreaseDecreaseFromRedemptions" xlink:label="cli_MinorityInterestIncreaseDecreaseFromRedemptions" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MinorityInterestIncreaseDecreaseFromRedemptions" xlink:to="cli_MinorityInterestIncreaseDecreaseFromRedemptions_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MinorityInterestIncreaseDecreaseFromRedemptions_lbl" xml:lang="en-US">Minority Interest, Increase (Decrease) From Redemptions</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MinorityInterestIncreaseDecreaseFromRedemptions_lbl" xml:lang="en-US">Minority Interest, Increase (Decrease) From Redemptions</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MinorityInterestIncreaseDecreaseFromRedemptions_lbl" xml:lang="en-US">Redemption of common units for common stock, value</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits" xlink:to="us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits_lbl" xml:lang="en-US">Stock Issued During Period, Shares, Conversion of Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits_lbl" xml:lang="en-US">Redemption of common units for shares of common stock, shares</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan" xlink:label="us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan" xlink:to="us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_lbl" xml:lang="en-US">Shares issued under Dividend Reinvestment and Stock Purchase Plan, value</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan" xlink:label="us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan" xlink:to="us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_lbl" xml:lang="en-US">Shares issued under Dividend Reinvestment and Stock Purchase Plan, shares</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" xlink:to="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross_lbl" xml:lang="en-US">Stock Issued During Period, Value, Restricted Stock Award, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross_lbl" xml:lang="en-US">Directors' deferred compensation plan, value</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue" xlink:label="cli_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue" xlink:to="cli_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue_lbl" xml:lang="en-US">Adjustments To Additional Paid In Capital Sharebased Compensation Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue_lbl" xml:lang="en-US">Adjustments To Additional Paid In Capital Sharebased Compensation Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationValue_lbl" xml:lang="en-US">Stock compensation, value</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:to="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" xml:lang="en-US">Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" xml:lang="en-US">Stock compensation, shares</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited" xlink:to="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited_lbl" xml:lang="en-US">Stock Issued During Period, Value, Share-based Compensation, Forfeited</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited_lbl" xml:lang="en-US">Cancellation of restricted shares, value</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_lbl" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_lbl" xml:lang="en-US">Cancellation of restricted shares, shares</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:to="us-gaap_OtherComprehensiveIncomeLossNetOfTax_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax_lbl" xml:lang="en-US">Other Comprehensive Income (Loss), Net of Tax</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax_lbl" xml:lang="en-US">Other comprehensive income</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance" xlink:label="cli_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance" xlink:to="cli_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance_lbl" xml:lang="en-US">Noncontrolling Interest, Increase (Decrease) from Subsidiary Equity Issuance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance_lbl" xml:lang="en-US">Noncontrolling Interest, Increase (Decrease) from Subsidiary Equity Issuance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance_lbl" xml:lang="en-US">Rebalancing of ownership percentage between parent and subsidiaries</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:label="us-gaap_StatementOfCashFlowsAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_StatementOfCashFlowsAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xml:lang="en-US">Consolidated Statements Of Cash Flows [Abstract]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US">CASH FLOWS FROM OPERATING ACTIVITIES</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US">Adjustments to reconcile net income to net cash provided by Operating activities:</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="us-gaap_DepreciationDepletionAndAmortization" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationDepletionAndAmortization" xlink:to="us-gaap_DepreciationDepletionAndAmortization_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DepreciationDepletionAndAmortization_lbl" xml:lang="en-US">Depreciation and amortization, including related intangible assets</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AmortizationOfDeferredStockUnits" xlink:label="cli_AmortizationOfDeferredStockUnits" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AmortizationOfDeferredStockUnits" xlink:to="cli_AmortizationOfDeferredStockUnits_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AmortizationOfDeferredStockUnits_lbl" xml:lang="en-US">Amortization Of Deferred Stock Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AmortizationOfDeferredStockUnits_lbl" xml:lang="en-US">Amortization Of Deferred Stock Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AmortizationOfDeferredStockUnits_lbl" xml:lang="en-US">Amortization of directors deferred compensation stock units</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AmortizationOfShareBasedCompensation" xlink:label="cli_AmortizationOfShareBasedCompensation" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AmortizationOfShareBasedCompensation" xlink:to="cli_AmortizationOfShareBasedCompensation_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AmortizationOfShareBasedCompensation_lbl" xml:lang="en-US">Amortization Of Share-based Compensation</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AmortizationOfShareBasedCompensation_lbl" xml:lang="en-US">Amortization Of Share-based Compensation</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AmortizationOfShareBasedCompensation_lbl" xml:lang="en-US">Amortization of stock compensation</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AmortizationOfFinancingCostsAndDiscounts" xlink:label="us-gaap_AmortizationOfFinancingCostsAndDiscounts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfFinancingCostsAndDiscounts" xlink:to="us-gaap_AmortizationOfFinancingCostsAndDiscounts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AmortizationOfFinancingCostsAndDiscounts_lbl" xml:lang="en-US">Amortization of deferred financing costs</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AmortizationOfDebtDiscountAndMarkToMarket" xlink:label="cli_AmortizationOfDebtDiscountAndMarkToMarket" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AmortizationOfDebtDiscountAndMarkToMarket" xlink:to="cli_AmortizationOfDebtDiscountAndMarkToMarket_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AmortizationOfDebtDiscountAndMarkToMarket_lbl" xml:lang="en-US">Amortization Of Debt Discount And Mark-To-Market</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AmortizationOfDebtDiscountAndMarkToMarket_lbl" xml:lang="en-US">Amortization Of Debt Discount And Mark-To-Market</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AmortizationOfDebtDiscountAndMarkToMarket_lbl" xml:lang="en-US">Amortization of debt discount and mark-to-market</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityMethodInvestmentDividendsOrDistributions" xlink:label="us-gaap_EquityMethodInvestmentDividendsOrDistributions" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentDividendsOrDistributions" xlink:to="us-gaap_EquityMethodInvestmentDividendsOrDistributions_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentDividendsOrDistributions_lbl" xml:lang="en-US">Equity Method Investment Dividends Or Distributions</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EquityMethodInvestmentDividendsOrDistributions_lbl" xml:lang="en-US">Distributions of cumulative earnings from unconsolidated joint ventures</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RealizedGainsLossOnDispositionOfAssetsIncludingDiscontinuedOperations" xlink:label="cli_RealizedGainsLossOnDispositionOfAssetsIncludingDiscontinuedOperations" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RealizedGainsLossOnDispositionOfAssetsIncludingDiscontinuedOperations" xlink:to="cli_RealizedGainsLossOnDispositionOfAssetsIncludingDiscontinuedOperations_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RealizedGainsLossOnDispositionOfAssetsIncludingDiscontinuedOperations_lbl" xml:lang="en-US">Realized Gains Loss On Disposition Of Assets, Including Discontinued Operations</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RealizedGainsLossOnDispositionOfAssetsIncludingDiscontinuedOperations_lbl" xml:lang="en-US">Realized Gains Loss On Disposition Of Assets, Including Discontinued Operations</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_RealizedGainsLossOnDispositionOfAssetsIncludingDiscontinuedOperations_lbl" xml:lang="en-US">Realized (gains) losses and unrealized losses on disposition of rental property, net</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:to="us-gaap_GainsLossesOnExtinguishmentOfDebt_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt_lbl" xml:lang="en-US">Gains (Losses) on Extinguishment of Debt</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt_lbl" xml:lang="en-US">Loss (gain) from extinguishment of debt</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt_lbl" xml:lang="en-US">Loss from extinguishment of debt, net</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xml:lang="en-US">Changes in operating assets and liabilities:</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_IncreaseDecreaseInUnbilledRentReceivables" xlink:label="cli_IncreaseDecreaseInUnbilledRentReceivables" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_IncreaseDecreaseInUnbilledRentReceivables" xlink:to="cli_IncreaseDecreaseInUnbilledRentReceivables_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_IncreaseDecreaseInUnbilledRentReceivables_lbl" xml:lang="en-US">Increase Decrease In Unbilled Rent Receivables</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_IncreaseDecreaseInUnbilledRentReceivables_lbl" xml:lang="en-US">Increase Decrease In Unbilled Rent Receivables</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_IncreaseDecreaseInUnbilledRentReceivables_lbl" xml:lang="en-US">Increase in unbilled rents receivable, net</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xml:lang="en-US">Increase in deferred charges and other assets, net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xml:lang="en-US">Increase in deferred charges, goodwill and other assets</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInLeasingReceivables" xlink:label="us-gaap_IncreaseDecreaseInLeasingReceivables" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInLeasingReceivables" xlink:to="us-gaap_IncreaseDecreaseInLeasingReceivables_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInLeasingReceivables_lbl" xml:lang="en-US">(Increase) decrease in accounts receivable, net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInLeasingReceivables_lbl" xml:lang="en-US">Decrease (increase) in accounts receivable, net</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_lbl" xml:lang="en-US">Increase (decrease) in accounts payable, accrued expenses and other liabilities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_lbl" xml:lang="en-US">Increase (decrease) in accounts payable, accrued expenses and other liabilities</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_IncreaseDecreaseInRentsReceivedInAdvanceAndSecurityDeposits" xlink:label="cli_IncreaseDecreaseInRentsReceivedInAdvanceAndSecurityDeposits" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_IncreaseDecreaseInRentsReceivedInAdvanceAndSecurityDeposits" xlink:to="cli_IncreaseDecreaseInRentsReceivedInAdvanceAndSecurityDeposits_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_IncreaseDecreaseInRentsReceivedInAdvanceAndSecurityDeposits_lbl" xml:lang="en-US">The net change during the reporting period in the amount at the balance sheet date including both: (a) rents and other amounts paid in advance by tenants and clients; and (b) security deposits paid in advance to protect the provider of a service, such as a lessor, against damage or nonpayment by the tenant (lessee) during the term of the agreement</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_IncreaseDecreaseInRentsReceivedInAdvanceAndSecurityDeposits_lbl" xml:lang="en-US">Increase Decrease In Rents Received In Advance And Security Deposits</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_IncreaseDecreaseInRentsReceivedInAdvanceAndSecurityDeposits_lbl" xml:lang="en-US">Decrease in rents received in advance and security deposits</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInInterestPayableNet" xlink:label="us-gaap_IncreaseDecreaseInInterestPayableNet" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInInterestPayableNet" xlink:to="us-gaap_IncreaseDecreaseInInterestPayableNet_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInInterestPayableNet_lbl" xml:lang="en-US">Decrease in accrued interest payable</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncreaseDecreaseInInterestPayableNet_lbl" xml:lang="en-US">Increase (decrease) in accrued interest payable</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xml:lang="en-US">Net cash provided by operating activities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xml:lang="en-US">Net cash provided by operating activities</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xml:lang="en-US">CASH FLOWS FROM INVESTING ACTIVITIES</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:to="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_lbl" xml:lang="en-US">Payments to Acquire Businesses, Net of Cash Acquired</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_lbl" xml:lang="en-US">Rental property acquisitions and related intangibles</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToAcquireAndDevelopRealEstate" xlink:label="us-gaap_PaymentsToAcquireAndDevelopRealEstate" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireAndDevelopRealEstate" xlink:to="us-gaap_PaymentsToAcquireAndDevelopRealEstate_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireAndDevelopRealEstate_lbl" xml:lang="en-US">Payments to Acquire and Develop Real Estate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquireAndDevelopRealEstate_lbl" xml:lang="en-US">Rental property additions and improvements</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PaymentsToAcquireAndDevelopRealEstate_lbl" xml:lang="en-US">Purchase price of property</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToDevelopRealEstateAssets" xlink:label="us-gaap_PaymentsToDevelopRealEstateAssets" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToDevelopRealEstateAssets" xlink:to="us-gaap_PaymentsToDevelopRealEstateAssets_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToDevelopRealEstateAssets_lbl" xml:lang="en-US">Payments to Develop Real Estate Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToDevelopRealEstateAssets_lbl" xml:lang="en-US">Development of rental property and other related costs</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromSaleOfBuildings" xlink:label="us-gaap_ProceedsFromSaleOfBuildings" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromSaleOfBuildings" xlink:to="us-gaap_ProceedsFromSaleOfBuildings_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromSaleOfBuildings_lbl" xml:lang="en-US">Net Sales Proceeds</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromSaleOfBuildings_lbl" xml:lang="en-US">Proceeds from the sales of rental property</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromDivestitureOfInterestInJointVenture" xlink:label="us-gaap_ProceedsFromDivestitureOfInterestInJointVenture" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromDivestitureOfInterestInJointVenture" xlink:to="us-gaap_ProceedsFromDivestitureOfInterestInJointVenture_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromDivestitureOfInterestInJointVenture_lbl" xml:lang="en-US">Proceeds from Divestiture of Interest in Joint Venture</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromDivestitureOfInterestInJointVenture_lbl" xml:lang="en-US">Proceeds from the sale of investments in unconsolidated joint ventures</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToAcquireNotesReceivable" xlink:label="us-gaap_PaymentsToAcquireNotesReceivable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireNotesReceivable" xlink:to="us-gaap_PaymentsToAcquireNotesReceivable_lbl" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquireNotesReceivable_lbl" xml:lang="en-US">Investments in notes receivable</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromCollectionOfLoansReceivable_lbl" xml:lang="en-US">Proceeds from Collection of Loans Receivable</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ProceedsFromCollectionOfLoansReceivable_lbl" xml:lang="en-US">Repayment of notes receivable</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToAcquireInterestInJointVenture" xlink:label="us-gaap_PaymentsToAcquireInterestInJointVenture" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireInterestInJointVenture" xlink:to="us-gaap_PaymentsToAcquireInterestInJointVenture_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireInterestInJointVenture_lbl" xml:lang="en-US">Investment in unconsolidated joint ventures</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PaymentsToAcquireInterestInJointVenture_lbl" xml:lang="en-US">Acquisition cost</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DistributionsInExcessOfCumulativeEarningsFromJvs" xlink:to="cli_DistributionsInExcessOfCumulativeEarningsFromJvs_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DistributionsInExcessOfCumulativeEarningsFromJvs_lbl" xml:lang="en-US">This item represents the amount of distributions in excess of net earnings, which represents a return of investment, received from unconsolidated joint ventures and subsidiaries; these investments are accounted for under the equity method of accounting.</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_DistributionsInExcessOfCumulativeEarningsFromJvs_lbl" xml:lang="en-US">Distributions in excess of cumulative earnings from unconsolidated joint ventures</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ProceedsFromInvestmentReceivable" xlink:to="cli_ProceedsFromInvestmentReceivable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ProceedsFromInvestmentReceivable_lbl" xml:lang="en-US">Proceeds From Investment Receivable</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ProceedsFromInvestmentReceivable_lbl" xml:lang="en-US">Proceeds From Investment Receivable</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ProceedsFromInvestmentReceivable_lbl" xml:lang="en-US">Proceeds from investment receivable</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInRestrictedCash" xlink:label="us-gaap_IncreaseDecreaseInRestrictedCash" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInRestrictedCash" xlink:to="us-gaap_IncreaseDecreaseInRestrictedCash_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInRestrictedCash_lbl" xml:lang="en-US">Increase Decrease In Restricted Cash</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInRestrictedCash_lbl" xml:lang="en-US">Decrease (increase) in restricted cash</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xml:lang="en-US">Net cash used in investing activities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xml:lang="en-US">Net cash provided by investing activities</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xml:lang="en-US">CASH FLOW FROM FINANCING ACTIVITIES</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromUnsecuredLinesOfCredit" xlink:to="us-gaap_ProceedsFromUnsecuredLinesOfCredit_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromUnsecuredLinesOfCredit_lbl" xml:lang="en-US">Borrowings from revolving credit facility</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RepaymentsOfLinesOfCredit" xlink:label="us-gaap_RepaymentsOfLinesOfCredit" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfLinesOfCredit" xlink:to="us-gaap_RepaymentsOfLinesOfCredit_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RepaymentsOfLinesOfCredit_lbl" xml:lang="en-US">Repayment of revolving credit facility and money market loans</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_RepaymentsOfLinesOfCredit_lbl" xml:lang="en-US">Repayment of revolving credit facility</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RepaymentsOfUnsecuredDebt" xlink:label="us-gaap_RepaymentsOfUnsecuredDebt" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfUnsecuredDebt" xlink:to="us-gaap_RepaymentsOfUnsecuredDebt_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RepaymentsOfUnsecuredDebt_lbl" xml:lang="en-US">Repayments of senior unsecured notes</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_RepaymentsOfUnsecuredDebt_lbl" xml:lang="en-US">Repayment of senior unsecured notes</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ProceedsFromUnsecuredTermLoan" xlink:label="cli_ProceedsFromUnsecuredTermLoan" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ProceedsFromUnsecuredTermLoan" xlink:to="cli_ProceedsFromUnsecuredTermLoan_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ProceedsFromUnsecuredTermLoan_lbl" xml:lang="en-US">Proceeds From Unsecured Term Loan</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ProceedsFromUnsecuredTermLoan_lbl" xml:lang="en-US">Proceeds From Unsecured Term Loan</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ProceedsFromUnsecuredTermLoan_lbl" xml:lang="en-US">Borrowings from unsecured term loan</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromIssuanceOfSecuredDebt" xlink:label="us-gaap_ProceedsFromIssuanceOfSecuredDebt" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfSecuredDebt" xlink:to="us-gaap_ProceedsFromIssuanceOfSecuredDebt_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOfSecuredDebt_lbl" xml:lang="en-US">Proceeds from Issuance of Secured Debt</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromIssuanceOfSecuredDebt_lbl" xml:lang="en-US">Proceeds from mortgages and loans payable</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RepaymentsOfSecuredDebt" xlink:label="us-gaap_RepaymentsOfSecuredDebt" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfSecuredDebt" xlink:to="us-gaap_RepaymentsOfSecuredDebt_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RepaymentsOfSecuredDebt_lbl" xml:lang="en-US">Repayment of mortgages, loans payable and other obligations</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_RepaymentsOfSecuredDebt_lbl" xml:lang="en-US">Repayment of mortgages, loans payable and other obligations</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PaymentsToAcquireMinorityInterest" xlink:label="cli_PaymentsToAcquireMinorityInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PaymentsToAcquireMinorityInterest" xlink:to="cli_PaymentsToAcquireMinorityInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PaymentsToAcquireMinorityInterest_lbl" xml:lang="en-US">Payments To Acquire Minority Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PaymentsToAcquireMinorityInterest_lbl" xml:lang="en-US">Payments To Acquire Minority Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_PaymentsToAcquireMinorityInterest_lbl" xml:lang="en-US">Acquisition of noncontrolling interests</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ProceedsFromIssuanceOfRedeemableNoncontrollingInterests" xlink:label="cli_ProceedsFromIssuanceOfRedeemableNoncontrollingInterests" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ProceedsFromIssuanceOfRedeemableNoncontrollingInterests" xlink:to="cli_ProceedsFromIssuanceOfRedeemableNoncontrollingInterests_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ProceedsFromIssuanceOfRedeemableNoncontrollingInterests_lbl" xml:lang="en-US">Proceeds From Issuance Of Redeemable Noncontrolling Interests</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ProceedsFromIssuanceOfRedeemableNoncontrollingInterests_lbl" xml:lang="en-US">Proceeds From Issuance Of Redeemable Noncontrolling Interests</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ProceedsFromIssuanceOfRedeemableNoncontrollingInterests_lbl" xml:lang="en-US">Issuance of redeemable noncontrolling interests, net</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_BusinessAcquisitionContingentConsiderationCashPaid" xlink:label="cli_BusinessAcquisitionContingentConsiderationCashPaid" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_BusinessAcquisitionContingentConsiderationCashPaid" xlink:to="cli_BusinessAcquisitionContingentConsiderationCashPaid_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_BusinessAcquisitionContingentConsiderationCashPaid_lbl" xml:lang="en-US">Business Acquisition, Contingent Consideration, Cash Paid</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_BusinessAcquisitionContingentConsiderationCashPaid_lbl" xml:lang="en-US">Business Acquisition, Contingent Consideration, Cash Paid</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_BusinessAcquisitionContingentConsiderationCashPaid_lbl" xml:lang="en-US">Payment of contingent consideration</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsOfFinancingCosts" xlink:label="us-gaap_PaymentsOfFinancingCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfFinancingCosts" xlink:to="us-gaap_PaymentsOfFinancingCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsOfFinancingCosts_lbl" xml:lang="en-US">Payment of financing costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsOfFinancingCosts_lbl" xml:lang="en-US">Payment of financing costs</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromPaymentsToMinorityShareholders" xlink:label="us-gaap_ProceedsFromPaymentsToMinorityShareholders" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromPaymentsToMinorityShareholders" xlink:to="us-gaap_ProceedsFromPaymentsToMinorityShareholders_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromPaymentsToMinorityShareholders_lbl" xml:lang="en-US">Proceeds from (Payments to) Noncontrolling Interests</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromPaymentsToMinorityShareholders_lbl" xml:lang="en-US">Contributions from (to) noncontrolling interests</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsOfCapitalDistribution" xlink:label="us-gaap_PaymentsOfCapitalDistribution" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfCapitalDistribution" xlink:to="us-gaap_PaymentsOfCapitalDistribution_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsOfCapitalDistribution_lbl" xml:lang="en-US">Payment of dividends and distributions</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsOfCapitalDistribution_lbl" xml:lang="en-US">Payment of dividends and distributions</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xml:lang="en-US">Net cash provided used in financing activities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xml:lang="en-US">Net cash provided by financing activities</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:to="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_lbl" xml:lang="en-US">Net (decrease) increase in cash and cash equivalents</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_lbl" xml:lang="en-US">Net (decrease) increase in cash and cash equivalents</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_lbl" xml:lang="en-US">Organization And Basis Of Presentation [Abstract]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OrganizationAndBasisOfPresentationTable" xlink:label="cli_OrganizationAndBasisOfPresentationTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OrganizationAndBasisOfPresentationTable" xlink:to="cli_OrganizationAndBasisOfPresentationTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OrganizationAndBasisOfPresentationTable_lbl" xml:lang="en-US">Organization And Basis Of Presentation [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OrganizationAndBasisOfPresentationTable_lbl" xml:lang="en-US">Organization And Basis Of Presentation [Table]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RecentTransactionsLineItems_lbl" xml:lang="en-US">Recent Transactions [Line Items]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RecentTransactionsTextBlock_lbl" xml:lang="en-US">Recent Transactions [Text Block]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_InvestmentsInUnconsolidatedJointVenturesTable_lbl" xml:lang="en-US">Investments In Unconsolidated Joint Ventures [Table]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DeferredChargesGoodwillAndOtherAssetsLineItems_lbl" xml:lang="en-US">Deferred Charges, Goodwill And Other Assets [Line Items]</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_SegmentReportingInformationLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentReportingInformationLineItems_lbl" xml:lang="en-US">Segment Reporting Information [Line Items]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentReportingDisclosureTextBlock" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingDisclosureTextBlock" xlink:to="us-gaap_SegmentReportingDisclosureTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl" xml:lang="en-US">Segment Reporting Disclosure Textblock</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl" xml:lang="en-US">Segment Reporting</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RelatedPartyTransactionsAbstract" xlink:label="us-gaap_RelatedPartyTransactionsAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsAbstract" xlink:to="us-gaap_RelatedPartyTransactionsAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionsAbstract_lbl" xml:lang="en-US">Related Party Transactions [Abstract]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:label="us-gaap_RelatedPartyTransactionsDisclosureTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:to="us-gaap_RelatedPartyTransactionsDisclosureTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionsDisclosureTextBlock_lbl" xml:lang="en-US">Related Party Transactions Disclosure [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RelatedPartyTransactionsDisclosureTextBlock_lbl" xml:lang="en-US">Related Party Transactions</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_QuarterlyFinancialDataAbstract" xlink:label="us-gaap_QuarterlyFinancialDataAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_QuarterlyFinancialDataAbstract" xlink:to="us-gaap_QuarterlyFinancialDataAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_QuarterlyFinancialDataAbstract_lbl" xml:lang="en-US">Condensed Quarterly Financial Information [Abstract]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_QuarterlyFinancialInformationTextBlock" xlink:label="us-gaap_QuarterlyFinancialInformationTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_QuarterlyFinancialInformationTextBlock" xlink:to="us-gaap_QuarterlyFinancialInformationTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_QuarterlyFinancialInformationTextBlock_lbl" xml:lang="en-US">Quarterly Financial Information [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_QuarterlyFinancialInformationTextBlock_lbl" xml:lang="en-US">Condensed Quarterly Financial Information</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationDisclosureAbstract" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationDisclosureAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateAndAccumulatedDepreciationDisclosureAbstract" xlink:to="us-gaap_RealEstateAndAccumulatedDepreciationDisclosureAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationDisclosureAbstract_lbl" xml:lang="en-US">Real Estate Investments And Accumulated Depreciation [Abstract]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationDisclosureTextBlock" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationDisclosureTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateAndAccumulatedDepreciationDisclosureTextBlock" xlink:to="us-gaap_RealEstateAndAccumulatedDepreciationDisclosureTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationDisclosureTextBlock_lbl" xml:lang="en-US">Real Estate and Accumulated Depreciation Disclosure [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationDisclosureTextBlock_lbl" xml:lang="en-US">Real Estate Investments And Accumulated Depreciation</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgageLoansOnRealEstateAbstract" xlink:label="us-gaap_MortgageLoansOnRealEstateAbstract" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MortgageLoansOnRealEstateAbstract" xlink:to="us-gaap_MortgageLoansOnRealEstateAbstract_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageLoansOnRealEstateAbstract_lbl" xml:lang="en-US">Mortgage Loans on Real Estate [Abstract]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgageLoansOnRealEstateByLoanDisclosureTextBlock" xlink:label="us-gaap_MortgageLoansOnRealEstateByLoanDisclosureTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MortgageLoansOnRealEstateByLoanDisclosureTextBlock" xlink:to="us-gaap_MortgageLoansOnRealEstateByLoanDisclosureTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageLoansOnRealEstateByLoanDisclosureTextBlock_lbl" xml:lang="en-US">Mortgage Loans on Real Estate, by Loan Disclosure [Text Block]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl" xml:lang="en-US">Property, Plant and Equipment, Policy [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl" xml:lang="en-US">Rental Property</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateHeldForDevelopmentAndSalePolicy" xlink:label="us-gaap_RealEstateHeldForDevelopmentAndSalePolicy" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateHeldForDevelopmentAndSalePolicy" xlink:to="us-gaap_RealEstateHeldForDevelopmentAndSalePolicy_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateHeldForDevelopmentAndSalePolicy_lbl" xml:lang="en-US">Real Estate Held for Development and Sale, Policy</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_RealEstateHeldForDevelopmentAndSalePolicy_lbl" xml:lang="en-US">Rental Property Held For Sale</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityMethodInvestmentsPolicy" xlink:label="us-gaap_EquityMethodInvestmentsPolicy" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentsPolicy" xlink:to="us-gaap_EquityMethodInvestmentsPolicy_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentsPolicy_lbl" xml:lang="en-US">Equity Method Investments, Policy</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EquityMethodInvestmentsPolicy_lbl" xml:lang="en-US">Investments In Unconsolidated Joint Ventures</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:to="us-gaap_CashAndCashEquivalentsPolicyTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock_lbl" xml:lang="en-US">Cash and Cash Equivalents, Policy [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock_lbl" xml:lang="en-US">Cash And Cash Equivalents</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DeferredFinancingCostsPolicyTextBlock" xlink:label="cli_DeferredFinancingCostsPolicyTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DeferredFinancingCostsPolicyTextBlock" xlink:to="cli_DeferredFinancingCostsPolicyTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DeferredFinancingCostsPolicyTextBlock_lbl" xml:lang="en-US">Disclosure of entity's accounting policy for costs incurred in connection with obtaining finance.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DeferredFinancingCostsPolicyTextBlock_lbl" xml:lang="en-US">Deferred Financing Costs Policy Text Block</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_DeferredFinancingCostsPolicyTextBlock_lbl" xml:lang="en-US">Deferred Financing Costs</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DeferredLeasingCostsPolicyTextBlock" xlink:label="cli_DeferredLeasingCostsPolicyTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DeferredLeasingCostsPolicyTextBlock" xlink:to="cli_DeferredLeasingCostsPolicyTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DeferredLeasingCostsPolicyTextBlock_lbl" xml:lang="en-US">Disclosure of the entity's accounting policy for costs incurred in connection with leases.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DeferredLeasingCostsPolicyTextBlock_lbl" xml:lang="en-US">Deferred Leasing Costs Policy Text Block</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_DeferredLeasingCostsPolicyTextBlock_lbl" xml:lang="en-US">Deferred Leasing Costs</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" xlink:to="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_lbl" xml:lang="en-US">Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_lbl" xml:lang="en-US">Goodwill</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativesPolicyTextBlock" xlink:label="us-gaap_DerivativesPolicyTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativesPolicyTextBlock" xlink:to="us-gaap_DerivativesPolicyTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativesPolicyTextBlock_lbl" xml:lang="en-US">Derivatives, Policy [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativesPolicyTextBlock_lbl" xml:lang="en-US">Derivative Instruments</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueRecognitionPolicyTextBlock" xlink:label="us-gaap_RevenueRecognitionPolicyTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRecognitionPolicyTextBlock" xlink:to="us-gaap_RevenueRecognitionPolicyTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenueRecognitionPolicyTextBlock_lbl" xml:lang="en-US">Revenue Recognition, Policy [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RevenueRecognitionPolicyTextBlock_lbl" xml:lang="en-US">Revenue Recognition</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AllowanceForDoubtfulAccountsPolicyPolicyTextBlock" xlink:label="cli_AllowanceForDoubtfulAccountsPolicyPolicyTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AllowanceForDoubtfulAccountsPolicyPolicyTextBlock" xlink:to="cli_AllowanceForDoubtfulAccountsPolicyPolicyTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AllowanceForDoubtfulAccountsPolicyPolicyTextBlock_lbl" xml:lang="en-US">Allowance For Doubtful Accounts Policy [Policy Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AllowanceForDoubtfulAccountsPolicyPolicyTextBlock_lbl" xml:lang="en-US">Allowance For Doubtful Accounts Policy [Policy Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AllowanceForDoubtfulAccountsPolicyPolicyTextBlock_lbl" xml:lang="en-US">Allowance For Doubtful Accounts</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxPolicyTextBlock" xlink:label="us-gaap_IncomeTaxPolicyTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxPolicyTextBlock" xlink:to="us-gaap_IncomeTaxPolicyTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_lbl" xml:lang="en-US">Income Tax, Policy [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_lbl" xml:lang="en-US">Income And Other Taxes</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EarningsPerSharePolicyTextBlock" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerSharePolicyTextBlock" xlink:to="us-gaap_EarningsPerSharePolicyTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock_lbl" xml:lang="en-US">Earnings Per Share, Policy [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock_lbl" xml:lang="en-US">Earnings Per Share Or Unit</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DividendsAndDistributionsPayablePolicyTextBlock" xlink:label="cli_DividendsAndDistributionsPayablePolicyTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DividendsAndDistributionsPayablePolicyTextBlock" xlink:to="cli_DividendsAndDistributionsPayablePolicyTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DividendsAndDistributionsPayablePolicyTextBlock_lbl" xml:lang="en-US">Disclosure of the entity's accounting policy for declaring and paying dividends and distributions.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DividendsAndDistributionsPayablePolicyTextBlock_lbl" xml:lang="en-US">Dividends And Distributions Payable Policy Text Block</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_DividendsAndDistributionsPayablePolicyTextBlock_lbl" xml:lang="en-US">Dividends And Distributions Payable</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_IssuanceCostsPolicyTextBlock" xlink:label="cli_IssuanceCostsPolicyTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_IssuanceCostsPolicyTextBlock" xlink:to="cli_IssuanceCostsPolicyTextBlock_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_IssuanceCostsPolicyTextBlock_lbl" xml:lang="en-US">Disclosure of the accounting policy for costs incurred in connection with stock issuances.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_IssuanceCostsPolicyTextBlock_lbl" xml:lang="en-US">Issuance Costs Policy Text Block</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_IssuanceCostsPolicyTextBlock_lbl" xml:lang="en-US">Costs Incurred For Stock Issuances</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:to="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_lbl" xml:lang="en-US">Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_lbl" xml:lang="en-US">Stock Compensation</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OtherComprehensiveIncomePolicyTextBlock" xlink:label="cli_OtherComprehensiveIncomePolicyTextBlock" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OtherComprehensiveIncomePolicyTextBlock" xlink:to="cli_OtherComprehensiveIncomePolicyTextBlock_lbl" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OtherComprehensiveIncomePolicyTextBlock_lbl" xml:lang="en-US">Other Comprehensive Income Policy Text Block</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SummaryOfCompanySEquityInEarningsLossOfUnconsolidatedJointVentures_lbl" xml:lang="en-US">Summary Of Company's Equity In Earnings (Loss) Of Unconsolidated Joint Ventures</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ScheduleOfEquityMethodInvestmentSummarizedFinancialInformationBalanceSheetTableTextBlock_lbl" xml:lang="en-US">Schedule of Equity Method Investment, Summarized Financial Information, Balance Sheet [Table Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ScheduleOfEquityMethodInvestmentSummarizedFinancialInformationBalanceSheetTableTextBlock_lbl" xml:lang="en-US">Schedule of Equity Method Investment, Summarized Financial Information, Balance Sheet [Table Text Block]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ScheduleOfUnsecuredCreditRatingOperatingPartnershipsTableTextBlock_lbl" xml:lang="en-US">Schedule Of Unsecured Credit Rating, Operating Partnerships [Table Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_ScheduleOfUnsecuredCreditRatingOperatingPartnershipsTableTextBlock_lbl" xml:lang="en-US">Schedule Of Interest Rate On Outstanding Borrowings Payable</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ScheduleOfDefinedLeverageRatioTableTextBlock_lbl" xml:lang="en-US">Schedule Of Defined Leverage Ratio [Table Text Block]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock_lbl" xml:lang="en-US">Schedule of Maturities of Long-term Debt [Table Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock_lbl" xml:lang="en-US">Schedule Of Principal Payments</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CommitmentsAndContingenciesDisclosureTable" xlink:label="cli_CommitmentsAndContingenciesDisclosureTable" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CommitmentsAndContingenciesDisclosureTable_lbl" xml:lang="en-US">Commitments And Contingencies Disclosure [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CommitmentsAndContingenciesDisclosureTable_lbl" xml:lang="en-US">Commitments And Contingencies Disclosure [Table]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CommitmentsAndContingenciesDisclosureLineItems_lbl" xml:lang="en-US">Commitments And Contingencies Disclosure [Line Items]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock_lbl" xml:lang="en-US">Future Minimum Rental Payments Of Ground Leases</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ScheduleOfFutureMinimumRentalsUnderNonCancelableOperatingLeaseTextBlock" xlink:label="cli_ScheduleOfFutureMinimumRentalsUnderNonCancelableOperatingLeaseTextBlock" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ScheduleOfFutureMinimumRentalsUnderNonCancelableOperatingLeaseTextBlock_lbl" xml:lang="en-US">Schedule Of Future Minimum Rentals Under Non-cancelable Operating Lease [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ScheduleOfFutureMinimumRentalsUnderNonCancelableOperatingLeaseTextBlock_lbl" xml:lang="en-US">Schedule Of Future Minimum Rentals Under Non-cancelable Operating Lease [Text Block]</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RedeemableNoncontrollingInterestTableTextBlock" xlink:label="us-gaap_RedeemableNoncontrollingInterestTableTextBlock" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RedeemableNoncontrollingInterestTableTextBlock_lbl" xml:lang="en-US">Redeemable Noncontrolling Interest [Table Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RedeemableNoncontrollingInterestTableTextBlock_lbl" xml:lang="en-US">Schedule Of Changes In The Value Of The Redeemable Noncontrolling Interests</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl" xml:lang="en-US">Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl" xml:lang="en-US">Schedule Of Stock Option Plans</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock_lbl" xml:lang="en-US">Schedule of Quarterly Financial Information [Table Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock_lbl" xml:lang="en-US">Summary Of Condensed Quarterly Financial Information</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis" xlink:label="us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis" xlink:to="us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_lbl" xml:lang="en-US">Real Estate, Type of Property [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgageLoansOnRealEstateNamePropertyTypeDomain" xlink:label="us-gaap_MortgageLoansOnRealEstateNamePropertyTypeDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MortgageLoansOnRealEstateNamePropertyTypeDomain" xlink:to="us-gaap_MortgageLoansOnRealEstateNamePropertyTypeDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageLoansOnRealEstateNamePropertyTypeDomain_lbl" xml:lang="en-US">Mortgage Loans On Real Estate Name Property Type [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MortgageLoansOnRealEstateNamePropertyTypeDomain_lbl" xml:lang="en-US">Real Estate [Domain]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OfficeAndOfficeFlexBuildingsMember" xlink:label="cli_OfficeAndOfficeFlexBuildingsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OfficeAndOfficeFlexBuildingsMember" xlink:to="cli_OfficeAndOfficeFlexBuildingsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OfficeAndOfficeFlexBuildingsMember_lbl" xml:lang="en-US">Office And Office Flex Buildings [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OfficeAndOfficeFlexBuildingsMember_lbl" xml:lang="en-US">Office And Office Flex Buildings [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OfficeAndOfficeFlexBuildingsMember_lbl" xml:lang="en-US">Office And Office/Flex Buildings [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_UnconsolidatedJointVentureOfficeBuildingsMember" xlink:label="cli_UnconsolidatedJointVentureOfficeBuildingsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_UnconsolidatedJointVentureOfficeBuildingsMember" xlink:to="cli_UnconsolidatedJointVentureOfficeBuildingsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_UnconsolidatedJointVentureOfficeBuildingsMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Office Buildings [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_UnconsolidatedJointVentureOfficeBuildingsMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Office Buildings [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_UnconsolidatedJointVentureOfficeBuildingsMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Office Buildings [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_IndustrialAndWarehouseFacilitiesMember" xlink:label="cli_IndustrialAndWarehouseFacilitiesMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_IndustrialAndWarehouseFacilitiesMember" xlink:to="cli_IndustrialAndWarehouseFacilitiesMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_IndustrialAndWarehouseFacilitiesMember_lbl" xml:lang="en-US">Industrial and Warehouse Facilities [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_IndustrialAndWarehouseFacilitiesMember_lbl" xml:lang="en-US">Industrial And Warehouse Facilities [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_IndustrialAndWarehouseFacilitiesMember_lbl" xml:lang="en-US">Industrial/Warehouse Facilities [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MultipleFamilyPropertiesMember" xlink:label="cli_MultipleFamilyPropertiesMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MultipleFamilyPropertiesMember" xlink:to="cli_MultipleFamilyPropertiesMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MultipleFamilyPropertiesMember_lbl" xml:lang="en-US">Multi-Family Properties [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MultipleFamilyPropertiesMember_lbl" xml:lang="en-US">Multiple Family Properties [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MultipleFamilyPropertiesMember_lbl" xml:lang="en-US">Multi-Family Properties [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_UnconsolidatedJointVentureMultipleFamilyPropertiesMember" xlink:label="cli_UnconsolidatedJointVentureMultipleFamilyPropertiesMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_UnconsolidatedJointVentureMultipleFamilyPropertiesMember" xlink:to="cli_UnconsolidatedJointVentureMultipleFamilyPropertiesMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_UnconsolidatedJointVentureMultipleFamilyPropertiesMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Multiple Family Properties [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_UnconsolidatedJointVentureMultipleFamilyPropertiesMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Multiple Family Properties [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_UnconsolidatedJointVentureMultipleFamilyPropertiesMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Multi-Family Properties [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_UnconsolidatedJointVentureOfficeFlexBuildingsAndHotelMember" xlink:label="cli_UnconsolidatedJointVentureOfficeFlexBuildingsAndHotelMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_UnconsolidatedJointVentureOfficeFlexBuildingsAndHotelMember" xlink:to="cli_UnconsolidatedJointVentureOfficeFlexBuildingsAndHotelMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_UnconsolidatedJointVentureOfficeFlexBuildingsAndHotelMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Office/Flex Buildings And Hotel [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_UnconsolidatedJointVentureOfficeFlexBuildingsAndHotelMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Office Flex Buildings And Hotel [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_UnconsolidatedJointVentureOfficeFlexBuildingsAndHotelMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Office/Flex Buildings And Hotel [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ParkingRetailMember" xlink:label="cli_ParkingRetailMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ParkingRetailMember" xlink:to="cli_ParkingRetailMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ParkingRetailMember_lbl" xml:lang="en-US">Parking/Retail [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ParkingRetailMember_lbl" xml:lang="en-US">Parking Retail [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ParkingRetailMember_lbl" xml:lang="en-US">Parking/Retail [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_UnconsolidatedJointVentureParkingRetailBuildingsMember" xlink:label="cli_UnconsolidatedJointVentureParkingRetailBuildingsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_UnconsolidatedJointVentureParkingRetailBuildingsMember" xlink:to="cli_UnconsolidatedJointVentureParkingRetailBuildingsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_UnconsolidatedJointVentureParkingRetailBuildingsMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Parking/Retail Buildings [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_UnconsolidatedJointVentureParkingRetailBuildingsMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Parking Retail Buildings [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_UnconsolidatedJointVentureParkingRetailBuildingsMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Parking/Retail Buildings [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LandMember" xlink:label="us-gaap_LandMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LandMember" xlink:to="us-gaap_LandMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LandMember_lbl" xml:lang="en-US">Land [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LandMember_lbl" xml:lang="en-US">Land [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_GeneralPartnerOwnershipPercentage" xlink:label="cli_GeneralPartnerOwnershipPercentage" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_GeneralPartnerOwnershipPercentage" xlink:to="cli_GeneralPartnerOwnershipPercentage_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_GeneralPartnerOwnershipPercentage_lbl" xml:lang="en-US">General Partner Ownership Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_GeneralPartnerOwnershipPercentage_lbl" xml:lang="en-US">General Partner Ownership Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_GeneralPartnerOwnershipPercentage_lbl" xml:lang="en-US">Percentage of ownership interest</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RealEstatePropertyOwnedAndInvestmentInterest" xlink:label="cli_RealEstatePropertyOwnedAndInvestmentInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RealEstatePropertyOwnedAndInvestmentInterest" xlink:to="cli_RealEstatePropertyOwnedAndInvestmentInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RealEstatePropertyOwnedAndInvestmentInterest_lbl" xml:lang="en-US">Real Estate Property Owned and Investment Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RealEstatePropertyOwnedAndInvestmentInterest_lbl" xml:lang="en-US">Real Estate Property Owned and Investment Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RealEstatePropertyOwnedAndInvestmentInterest_lbl" xml:lang="en-US">Number of properties owned or investment interests</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RealEstatePropertyOwnedAndInvestmentInterestArea" xlink:label="cli_RealEstatePropertyOwnedAndInvestmentInterestArea" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RealEstatePropertyOwnedAndInvestmentInterestArea" xlink:to="cli_RealEstatePropertyOwnedAndInvestmentInterestArea_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RealEstatePropertyOwnedAndInvestmentInterestArea_lbl" xml:lang="en-US">Real Estate Property Owned and Investment Interest, Area</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RealEstatePropertyOwnedAndInvestmentInterestArea_lbl" xml:lang="en-US">Real Estate Property Owned and Investment Interest, Area</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RealEstatePropertyOwnedAndInvestmentInterestArea_lbl" xml:lang="en-US">Aggregate square feet of the property owned or investment interest</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfTenants" xlink:label="cli_NumberOfTenants" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfTenants" xlink:to="cli_NumberOfTenants_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfTenants_lbl" xml:lang="en-US">Number Of Tenants</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfTenants_lbl" xml:lang="en-US">Number Of Tenants</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfTenants_lbl" xml:lang="en-US">Number of tenants</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NumberOfUnitsInRealEstateProperty" xlink:label="us-gaap_NumberOfUnitsInRealEstateProperty" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfUnitsInRealEstateProperty" xlink:to="us-gaap_NumberOfUnitsInRealEstateProperty_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NumberOfUnitsInRealEstateProperty_lbl" xml:lang="en-US">Number Of Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:label="us-gaap_NumberOfUnitsInRealEstateProperty_lbl" xml:lang="en-US">Number of rental units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NumberOfUnitsInRealEstateProperty_lbl" xml:lang="en-US">Number of Apartment Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_NumberOfUnitsInRealEstateProperty_lbl" xml:lang="en-US">Number of units</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RealEstatePropertyOwnedOrInvestmentInterestNumberOfLocation" xlink:label="cli_RealEstatePropertyOwnedOrInvestmentInterestNumberOfLocation" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RealEstatePropertyOwnedOrInvestmentInterestNumberOfLocation" xlink:to="cli_RealEstatePropertyOwnedOrInvestmentInterestNumberOfLocation_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RealEstatePropertyOwnedOrInvestmentInterestNumberOfLocation_lbl" xml:lang="en-US">Real Estate Property Owned or Investment Interest, Number of Location</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RealEstatePropertyOwnedOrInvestmentInterestNumberOfLocation_lbl" xml:lang="en-US">Real Estate Property Owned or Investment Interest, Number of Location</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_RealEstatePropertyOwnedOrInvestmentInterestNumberOfLocation_lbl" xml:lang="en-US">Number of states where properties are located</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ConsolidatedJointVenturesRealEstateAssets" xlink:label="cli_ConsolidatedJointVenturesRealEstateAssets" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ConsolidatedJointVenturesRealEstateAssets" xlink:to="cli_ConsolidatedJointVenturesRealEstateAssets_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ConsolidatedJointVenturesRealEstateAssets_lbl" xml:lang="en-US">Consolidated Joint Ventures Real Estate Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ConsolidatedJointVenturesRealEstateAssets_lbl" xml:lang="en-US">Consolidated Joint Ventures Real Estate Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ConsolidatedJointVenturesRealEstateAssets_lbl" xml:lang="en-US">Consolidated joint ventures, total real estate assets</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ConsolidatedJointVenturesMortgages" xlink:label="cli_ConsolidatedJointVenturesMortgages" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ConsolidatedJointVenturesMortgages" xlink:to="cli_ConsolidatedJointVenturesMortgages_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ConsolidatedJointVenturesMortgages_lbl" xml:lang="en-US">Consolidated Joint Ventures Mortgages</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ConsolidatedJointVenturesMortgages_lbl" xml:lang="en-US">Consolidated Joint Ventures Mortgages</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ConsolidatedJointVenturesMortgages_lbl" xml:lang="en-US">Consolidated joint ventures, mortgages</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ConsolidatedJointVenturesOtherLiabilities" xlink:label="cli_ConsolidatedJointVenturesOtherLiabilities" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ConsolidatedJointVenturesOtherLiabilities" xlink:to="cli_ConsolidatedJointVenturesOtherLiabilities_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ConsolidatedJointVenturesOtherLiabilities_lbl" xml:lang="en-US">Consolidated Joint Ventures Other Liabilities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ConsolidatedJointVenturesOtherLiabilities_lbl" xml:lang="en-US">Consolidated Joint Ventures Other Liabilities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ConsolidatedJointVenturesOtherLiabilities_lbl" xml:lang="en-US">Consolidated joint ventures, other liabilities</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CapitalizedDevelopmentConstructionSalariesAndOtherRelatedExpenses" xlink:label="cli_CapitalizedDevelopmentConstructionSalariesAndOtherRelatedExpenses" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CapitalizedDevelopmentConstructionSalariesAndOtherRelatedExpenses" xlink:to="cli_CapitalizedDevelopmentConstructionSalariesAndOtherRelatedExpenses_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CapitalizedDevelopmentConstructionSalariesAndOtherRelatedExpenses_lbl" xml:lang="en-US">Capitalized Development, Construction Salaries And Other Related Expenses</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CapitalizedDevelopmentConstructionSalariesAndOtherRelatedExpenses_lbl" xml:lang="en-US">Capitalized Development, Construction Salaries And Other Related Expenses</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_CapitalizedDevelopmentConstructionSalariesAndOtherRelatedExpenses_lbl" xml:lang="en-US">Capitalized development and construction salaries and other related costs</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConstructionInProgressGross" xlink:label="us-gaap_ConstructionInProgressGross" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConstructionInProgressGross" xlink:to="us-gaap_ConstructionInProgressGross_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConstructionInProgressGross_lbl" xml:lang="en-US">Construction in Progress, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConstructionInProgressGross_lbl" xml:lang="en-US">Construction, tenant improvement, and development in-progress</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MaximumPeriodAfterCessationOfMajorConstructionActivityThatProjectsAreConsideredComplete" xlink:label="cli_MaximumPeriodAfterCessationOfMajorConstructionActivityThatProjectsAreConsideredComplete" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MaximumPeriodAfterCessationOfMajorConstructionActivityThatProjectsAreConsideredComplete" xlink:to="cli_MaximumPeriodAfterCessationOfMajorConstructionActivityThatProjectsAreConsideredComplete_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MaximumPeriodAfterCessationOfMajorConstructionActivityThatProjectsAreConsideredComplete_lbl" xml:lang="en-US">Maximum Period After Cessation Of Major Construction Activity That Projects Are Considered Complete</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MaximumPeriodAfterCessationOfMajorConstructionActivityThatProjectsAreConsideredComplete_lbl" xml:lang="en-US">Maximum Period After Cessation Of Major Construction Activity That Projects Are Considered Complete</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MaximumPeriodAfterCessationOfMajorConstructionActivityThatProjectsAreConsideredComplete_lbl" xml:lang="en-US">Maximum period after cessation of major construction activity that projects are considered complete</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThresholdOfInvestmentValueForDiscontinuationOfEquityMethodAccounting" xlink:label="cli_ThresholdOfInvestmentValueForDiscontinuationOfEquityMethodAccounting" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThresholdOfInvestmentValueForDiscontinuationOfEquityMethodAccounting" xlink:to="cli_ThresholdOfInvestmentValueForDiscontinuationOfEquityMethodAccounting_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThresholdOfInvestmentValueForDiscontinuationOfEquityMethodAccounting_lbl" xml:lang="en-US">Threshold Of Investment Value For Discontinuation Of Equity Method Accounting</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThresholdOfInvestmentValueForDiscontinuationOfEquityMethodAccounting_lbl" xml:lang="en-US">Threshold Of Investment Value For Discontinuation Of Equity Method Accounting</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThresholdOfInvestmentValueForDiscontinuationOfEquityMethodAccounting_lbl" xml:lang="en-US">Threshold of investment value for discontinuation of equity method accounting</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AmortizationOfFinancingCosts" xlink:label="us-gaap_AmortizationOfFinancingCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfFinancingCosts" xlink:to="us-gaap_AmortizationOfFinancingCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AmortizationOfFinancingCosts_lbl" xml:lang="en-US">Amortization of Financing Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AmortizationOfFinancingCosts_lbl" xml:lang="en-US">Amortization of deferred financing costs</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_WriteOffOfUnamortizedDeferredFinancingCosts" xlink:label="cli_WriteOffOfUnamortizedDeferredFinancingCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_WriteOffOfUnamortizedDeferredFinancingCosts" xlink:to="cli_WriteOffOfUnamortizedDeferredFinancingCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_WriteOffOfUnamortizedDeferredFinancingCosts_lbl" xml:lang="en-US">Write off of Unamortized Deferred Financing Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_WriteOffOfUnamortizedDeferredFinancingCosts_lbl" xml:lang="en-US">Write off of Unamortized Deferred Financing Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_WriteOffOfUnamortizedDeferredFinancingCosts_lbl" xml:lang="en-US">Write off of unamortized deferred financing costs</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AmortizationOfDeferredLeasingFees" xlink:label="us-gaap_AmortizationOfDeferredLeasingFees" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfDeferredLeasingFees" xlink:to="us-gaap_AmortizationOfDeferredLeasingFees_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AmortizationOfDeferredLeasingFees_lbl" xml:lang="en-US">Amortization of Deferred Leasing Fees</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AmortizationOfDeferredLeasingFees_lbl" xml:lang="en-US">Deferred leasing costs</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EntityNotSubjectToIncomeTaxesDifferenceInBasesAmount" xlink:label="us-gaap_EntityNotSubjectToIncomeTaxesDifferenceInBasesAmount" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EntityNotSubjectToIncomeTaxesDifferenceInBasesAmount" xlink:to="us-gaap_EntityNotSubjectToIncomeTaxesDifferenceInBasesAmount_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EntityNotSubjectToIncomeTaxesDifferenceInBasesAmount_lbl" xml:lang="en-US">Entity Not Subject to Income Taxes, Difference in Bases, Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EntityNotSubjectToIncomeTaxesDifferenceInBasesAmount_lbl" xml:lang="en-US">Difference between the estimated net basis and net assets of the rental property for federal income tax purposes</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TaxableIncome" xlink:label="cli_TaxableIncome" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TaxableIncome" xlink:to="cli_TaxableIncome_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TaxableIncome_lbl" xml:lang="en-US">Taxable Income</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TaxableIncome_lbl" xml:lang="en-US">Taxable Income</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TaxableIncome_lbl" xml:lang="en-US">Taxable income</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsValuationAllowance" xlink:to="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xml:lang="en-US">Deferred tax asset</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MaterialAdjustmentAmount" xlink:label="cli_MaterialAdjustmentAmount" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MaterialAdjustmentAmount" xlink:to="cli_MaterialAdjustmentAmount_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MaterialAdjustmentAmount_lbl" xml:lang="en-US">Material Adjustment Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MaterialAdjustmentAmount_lbl" xml:lang="en-US">Material Adjustment Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MaterialAdjustmentAmount_lbl" xml:lang="en-US">Income taxes, material adjustment amount</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CommonUnitsOutstanding" xlink:label="cli_CommonUnitsOutstanding" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CommonUnitsOutstanding" xlink:to="cli_CommonUnitsOutstanding_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CommonUnitsOutstanding_lbl" xml:lang="en-US">The number of common units outstanding.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CommonUnitsOutstanding_lbl" xml:lang="en-US">Common Units Outstanding</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="cli_CommonUnitsOutstanding_lbl" xml:lang="en-US">Balance, Ending, Common Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="cli_CommonUnitsOutstanding_lbl" xml:lang="en-US">Balance, Beginning, Common Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_CommonUnitsOutstanding_lbl" xml:lang="en-US">Common units outstanding</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LongTermIncentivePlanUnitsOutstanding" xlink:label="cli_LongTermIncentivePlanUnitsOutstanding" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LongTermIncentivePlanUnitsOutstanding" xlink:to="cli_LongTermIncentivePlanUnitsOutstanding_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LongTermIncentivePlanUnitsOutstanding_lbl" xml:lang="en-US">Long-Term Incentive Plan Units Outstanding</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LongTermIncentivePlanUnitsOutstanding_lbl" xml:lang="en-US">Long-Term Incentive Plan Units Outstanding</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="cli_LongTermIncentivePlanUnitsOutstanding_lbl" xml:lang="en-US">Balance, Ending, LTIP Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="cli_LongTermIncentivePlanUnitsOutstanding_lbl" xml:lang="en-US">Balance, Beginning, LTIP Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_LongTermIncentivePlanUnitsOutstanding_lbl" xml:lang="en-US">LTIP units outstanding</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DividendsPayableDateOfRecordDayMonthAndYear" xlink:label="us-gaap_DividendsPayableDateOfRecordDayMonthAndYear" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendsPayableDateOfRecordDayMonthAndYear" xlink:to="us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_lbl" xml:lang="en-US">Dividends Payable, Date of Record</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_lbl" xml:lang="en-US">Distributions payable, record date</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DividendsPayableDateDeclaredDayMonthAndYear" xlink:label="us-gaap_DividendsPayableDateDeclaredDayMonthAndYear" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendsPayableDateDeclaredDayMonthAndYear" xlink:to="us-gaap_DividendsPayableDateDeclaredDayMonthAndYear_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DividendsPayableDateDeclaredDayMonthAndYear_lbl" xml:lang="en-US">Dividends Payable, Date Declared</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DividendsPayableDateDeclaredDayMonthAndYear_lbl" xml:lang="en-US">Distributions payable, approved date</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CommonStockDividendsAndCommonUnitDistributionsPerShare" xlink:label="cli_CommonStockDividendsAndCommonUnitDistributionsPerShare" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CommonStockDividendsAndCommonUnitDistributionsPerShare" xlink:to="cli_CommonStockDividendsAndCommonUnitDistributionsPerShare_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CommonStockDividendsAndCommonUnitDistributionsPerShare_lbl" xml:lang="en-US">Common Stock Dividends And Common Unit Distributions Per Share</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CommonStockDividendsAndCommonUnitDistributionsPerShare_lbl" xml:lang="en-US">Common Stock Dividends And Common Unit Distributions Per Share</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_CommonStockDividendsAndCommonUnitDistributionsPerShare_lbl" xml:lang="en-US">Common stock dividends and common unit distributions per share</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockDividendsPerShareCashPaid" xlink:label="us-gaap_CommonStockDividendsPerShareCashPaid" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockDividendsPerShareCashPaid" xlink:to="us-gaap_CommonStockDividendsPerShareCashPaid_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockDividendsPerShareCashPaid_lbl" xml:lang="en-US">Common Stock, Dividends, Per Share, Cash Paid</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockDividendsPerShareCashPaid_lbl" xml:lang="en-US">Dividends paid per common share</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CommonStockDividendsPerSharePaidPercentRepresentingOrdinaryIncome" xlink:label="cli_CommonStockDividendsPerSharePaidPercentRepresentingOrdinaryIncome" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CommonStockDividendsPerSharePaidPercentRepresentingOrdinaryIncome" xlink:to="cli_CommonStockDividendsPerSharePaidPercentRepresentingOrdinaryIncome_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CommonStockDividendsPerSharePaidPercentRepresentingOrdinaryIncome_lbl" xml:lang="en-US">Common Stock Dividends Per Share Paid Percent Representing Ordinary Income</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CommonStockDividendsPerSharePaidPercentRepresentingOrdinaryIncome_lbl" xml:lang="en-US">Common Stock Dividends Per Share Paid Percent Representing Ordinary Income</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_CommonStockDividendsPerSharePaidPercentRepresentingOrdinaryIncome_lbl" xml:lang="en-US">Dividends paid, percent representing ordinary income</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CommonStockDividendsPerSharePaidPercentRepresentingReturnOfCapitalToStockholders" xlink:label="cli_CommonStockDividendsPerSharePaidPercentRepresentingReturnOfCapitalToStockholders" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CommonStockDividendsPerSharePaidPercentRepresentingReturnOfCapitalToStockholders" xlink:to="cli_CommonStockDividendsPerSharePaidPercentRepresentingReturnOfCapitalToStockholders_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CommonStockDividendsPerSharePaidPercentRepresentingReturnOfCapitalToStockholders_lbl" xml:lang="en-US">Common Stock Dividends Per Share Paid Percent Representing Return Of Capital To Stockholders</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CommonStockDividendsPerSharePaidPercentRepresentingReturnOfCapitalToStockholders_lbl" xml:lang="en-US">Common Stock Dividends Per Share Paid Percent Representing Return Of Capital To Stockholders</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_CommonStockDividendsPerSharePaidPercentRepresentingReturnOfCapitalToStockholders_lbl" xml:lang="en-US">Dividends paid, percent representing return of capital to shareholders</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CommonStockDividendsPerSharePaidPercentRepresentingCapitalGain" xlink:label="cli_CommonStockDividendsPerSharePaidPercentRepresentingCapitalGain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CommonStockDividendsPerSharePaidPercentRepresentingCapitalGain" xlink:to="cli_CommonStockDividendsPerSharePaidPercentRepresentingCapitalGain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CommonStockDividendsPerSharePaidPercentRepresentingCapitalGain_lbl" xml:lang="en-US">Common Stock Dividends Per Share Paid, Percent Representing Capital Gain</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CommonStockDividendsPerSharePaidPercentRepresentingCapitalGain_lbl" xml:lang="en-US">Common Stock Dividends Per Share Paid, Percent Representing Capital Gain</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_CommonStockDividendsPerSharePaidPercentRepresentingCapitalGain_lbl" xml:lang="en-US">Dividends paid, percent representing capital gain</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestrictedStockExpense" xlink:label="us-gaap_RestrictedStockExpense" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockExpense" xlink:to="us-gaap_RestrictedStockExpense_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RestrictedStockExpense_lbl" xml:lang="en-US">Restricted Stock Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RestrictedStockExpense_lbl" xml:lang="en-US">Restricted stock expense</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DividendPayableDateToBePaidDayMonthAndYear" xlink:label="us-gaap_DividendPayableDateToBePaidDayMonthAndYear" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendPayableDateToBePaidDayMonthAndYear" xlink:to="us-gaap_DividendPayableDateToBePaidDayMonthAndYear_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DividendPayableDateToBePaidDayMonthAndYear_lbl" xml:lang="en-US">Dividends Payable, Date to be Paid, Day, Month and Year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DividendPayableDateToBePaidDayMonthAndYear_lbl" xml:lang="en-US">Distributions payable, pay date</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TaxCutsAndJobsActOf2017IncompleteAccountingChangeIn" xlink:label="cli_TaxCutsAndJobsActOf2017IncompleteAccountingChangeIn" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TaxCutsAndJobsActOf2017IncompleteAccountingChangeIn" xlink:to="cli_TaxCutsAndJobsActOf2017IncompleteAccountingChangeIn_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TaxCutsAndJobsActOf2017IncompleteAccountingChangeIn_lbl" xml:lang="en-US">Tax Cuts And Jobs Act of 2017, Incomplete Accounting, Change In Tax Rate, Provisional Income Tax Expense (Benefit)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TaxCutsAndJobsActOf2017IncompleteAccountingChangeIn_lbl" xml:lang="en-US">Tax Cuts And Jobs Act of 2017, Incomplete Accounting, Change In</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TaxCutsAndJobsActOf2017IncompleteAccountingChangeIn_lbl" xml:lang="en-US">Increase (decrease) to deferred tax assets</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount" xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount" xlink:to="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_lbl" xml:lang="en-US">Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_lbl" xml:lang="en-US">Increase (decrease) to valuation allowance</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" xml:lang="en-US">Schedule of Property, Plant and Equipment [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeAxis" xlink:label="us-gaap_RangeAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RangeAxis" xlink:to="us-gaap_RangeAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RangeAxis_lbl" xml:lang="en-US">Range [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeMember" xlink:label="us-gaap_RangeMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RangeMember" xlink:to="us-gaap_RangeMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RangeMember_lbl" xml:lang="en-US">Range [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RangeMember_lbl" xml:lang="en-US">Range [Domain]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinimumMember" xlink:label="us-gaap_MinimumMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinimumMember" xlink:to="us-gaap_MinimumMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MinimumMember_lbl" xml:lang="en-US">Minimum [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MinimumMember_lbl" xml:lang="en-US">Minimum [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MaximumMember" xlink:label="us-gaap_MaximumMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MaximumMember" xlink:to="us-gaap_MaximumMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MaximumMember_lbl" xml:lang="en-US">Maximum [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MaximumMember_lbl" xml:lang="en-US">Maximum [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xml:lang="en-US">Property, Plant and Equipment by Type [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xml:lang="en-US">Property Plant And Equipment Type [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xml:lang="en-US">Property, Plant and Equipment, Type [Domain]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BuildingAndBuildingImprovementsMember" xlink:label="us-gaap_BuildingAndBuildingImprovementsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BuildingAndBuildingImprovementsMember" xlink:to="us-gaap_BuildingAndBuildingImprovementsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BuildingAndBuildingImprovementsMember_lbl" xml:lang="en-US">Building And Building Improvements [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BuildingAndBuildingImprovementsMember_lbl" xml:lang="en-US">Buildings And Improvements [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="us-gaap_FurnitureAndFixturesMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FurnitureAndFixturesMember" xlink:to="us-gaap_FurnitureAndFixturesMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FurnitureAndFixturesMember_lbl" xml:lang="en-US">Furniture And Fixtures [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FurnitureAndFixturesMember_lbl" xml:lang="en-US">Furniture, Fixtures And Equipment [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xml:lang="en-US">Property, Plant and Equipment [Line Items]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" xml:lang="en-US">Property, Plant and Equipment, Useful Life</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" xml:lang="en-US">Estimated useful lives of assets</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NumberOfRealEstateProperties" xlink:label="us-gaap_NumberOfRealEstateProperties" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfRealEstateProperties" xlink:to="us-gaap_NumberOfRealEstateProperties_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NumberOfRealEstateProperties_lbl" xml:lang="en-US">Number of real estate properties</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NumberOfRealEstateProperties_lbl" xml:lang="en-US">Number of properties</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AreaOfRealEstateProperty" xlink:label="us-gaap_AreaOfRealEstateProperty" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AreaOfRealEstateProperty" xlink:to="us-gaap_AreaOfRealEstateProperty_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AreaOfRealEstateProperty_lbl" xml:lang="en-US">Area Of Real Estate Property</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:label="us-gaap_AreaOfRealEstateProperty_lbl" xml:lang="en-US">Area of property (in square feet)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AreaOfRealEstateProperty_lbl" xml:lang="en-US">Rentable Square Feet (sf)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AreaOfRealEstateProperty_lbl" xml:lang="en-US">Area of property (in square feet)</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PreferredUnitsIssued" xlink:label="us-gaap_PreferredUnitsIssued" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredUnitsIssued" xlink:to="us-gaap_PreferredUnitsIssued_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredUnitsIssued_lbl" xml:lang="en-US">Preferred Units, Issued</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredUnitsIssued_lbl" xml:lang="en-US">Preferred units shares issued</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfTowersInRealEstateProperty" xlink:label="cli_NumberOfTowersInRealEstateProperty" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfTowersInRealEstateProperty" xlink:to="cli_NumberOfTowersInRealEstateProperty_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfTowersInRealEstateProperty_lbl" xml:lang="en-US">Number Of Towers In Real Estate Property</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfTowersInRealEstateProperty_lbl" xml:lang="en-US">Number Of Towers In Real Estate Property</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfTowersInRealEstateProperty_lbl" xml:lang="en-US">Number of towers</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:to="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xml:lang="en-US">Equity Method Investment, Ownership Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xml:lang="en-US">Percentage of interest in venture</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xml:lang="en-US">Company's Effective Ownership %</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_lbl" xml:lang="en-US">Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_lbl" xml:lang="en-US">Loans assumed</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PreferredUnitDividendRatePercentage" xlink:label="cli_PreferredUnitDividendRatePercentage" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PreferredUnitDividendRatePercentage" xlink:to="cli_PreferredUnitDividendRatePercentage_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PreferredUnitDividendRatePercentage_lbl" xml:lang="en-US">Preferred Unit, Dividend Rate, Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PreferredUnitDividendRatePercentage_lbl" xml:lang="en-US">Preferred Unit, Dividend Rate, Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PreferredUnitDividendRatePercentage_lbl" xml:lang="en-US">Preferred unit annual rate</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PreferredUnitsPreferredPartnersCapitalAccounts" xlink:label="us-gaap_PreferredUnitsPreferredPartnersCapitalAccounts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredUnitsPreferredPartnersCapitalAccounts" xlink:to="us-gaap_PreferredUnitsPreferredPartnersCapitalAccounts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredUnitsPreferredPartnersCapitalAccounts_lbl" xml:lang="en-US">Preferred Units, Preferred Partners' Capital Accounts</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredUnitsPreferredPartnersCapitalAccounts_lbl" xml:lang="en-US">Preferred units aggregate amount</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PercentageOfAdditionalInterestAcquired" xlink:label="cli_PercentageOfAdditionalInterestAcquired" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PercentageOfAdditionalInterestAcquired" xlink:to="cli_PercentageOfAdditionalInterestAcquired_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PercentageOfAdditionalInterestAcquired_lbl" xml:lang="en-US">Percentage Of Additional Interest Acquired</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PercentageOfAdditionalInterestAcquired_lbl" xml:lang="en-US">Percentage Of Additional Interest Acquired</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PercentageOfAdditionalInterestAcquired_lbl" xml:lang="en-US">Percentage of additional interest acquired</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_lbl" xml:lang="en-US">Business Acquisition, Purchase Price Allocation, Assets Acquired (Liabilities Assumed), Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_lbl" xml:lang="en-US">Net assets acquired</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_lbl" xml:lang="en-US">Net assets recorded upon acquisition</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfParkingSpaces" xlink:label="cli_NumberOfParkingSpaces" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfParkingSpaces" xlink:to="cli_NumberOfParkingSpaces_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfParkingSpaces_lbl" xml:lang="en-US">Number Of Parking Spaces</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfParkingSpaces_lbl" xml:lang="en-US">Number Of Parking Spaces</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfParkingSpaces_lbl" xml:lang="en-US">Number of parking spaces</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_NumberOfParkingSpaces_lbl" xml:lang="en-US">Garage Parking Spaces</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfStoriesInRealEstateProperty" xlink:label="cli_NumberOfStoriesInRealEstateProperty" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfStoriesInRealEstateProperty" xlink:to="cli_NumberOfStoriesInRealEstateProperty_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfStoriesInRealEstateProperty_lbl" xml:lang="en-US">Number Of Stories In Real Estate Property</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfStoriesInRealEstateProperty_lbl" xml:lang="en-US">Number Of Stories In Real Estate Property</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfStoriesInRealEstateProperty_lbl" xml:lang="en-US">Number of stories</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1" xlink:label="us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1" xlink:to="us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1_lbl" xml:lang="en-US">Noncash or Part Noncash Acquisition, Debt Assumed</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1_lbl" xml:lang="en-US">Debt assumed</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinorityInterestOwnershipPercentageByParent" xlink:label="us-gaap_MinorityInterestOwnershipPercentageByParent" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinorityInterestOwnershipPercentageByParent" xlink:to="us-gaap_MinorityInterestOwnershipPercentageByParent_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MinorityInterestOwnershipPercentageByParent_lbl" xml:lang="en-US">Noncontrolling Interest, Ownership Percentage by Parent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MinorityInterestOwnershipPercentageByParent_lbl" xml:lang="en-US">Parent ownership percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_MinorityInterestOwnershipPercentageByParent_lbl" xml:lang="en-US">Percentage of interest in venture</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MortgageLoanMaturityDate" xlink:label="cli_MortgageLoanMaturityDate" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MortgageLoanMaturityDate" xlink:to="cli_MortgageLoanMaturityDate_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MortgageLoanMaturityDate_lbl" xml:lang="en-US">Mortgage Loan Maturity Date</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MortgageLoanMaturityDate_lbl" xml:lang="en-US">Mortgage Loan Maturity Date</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MortgageLoanMaturityDate_lbl" xml:lang="en-US">Mortgage loan, maturity date</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_MortgageLoanMaturityDate_lbl" xml:lang="en-US">Property Debt, Maturity Date</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:to="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl" xml:lang="en-US">Property Debt, Interest Rate, Spread Over LIBOR</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl" xml:lang="en-US">Spread over LIBOR</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl" xml:lang="en-US">Interest Rate - Applicable Basis Points Above LIBOR</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgageLoansOnRealEstateCarryingAmountOfMortgages" xlink:label="us-gaap_MortgageLoansOnRealEstateCarryingAmountOfMortgages" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MortgageLoansOnRealEstateCarryingAmountOfMortgages" xlink:to="us-gaap_MortgageLoansOnRealEstateCarryingAmountOfMortgages_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageLoansOnRealEstateCarryingAmountOfMortgages_lbl" xml:lang="en-US">Property Debt, Balance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MortgageLoansOnRealEstateCarryingAmountOfMortgages_lbl" xml:lang="en-US">Carrying Amount of Mortgages</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_MortgageLoansOnRealEstateCarryingAmountOfMortgages_lbl" xml:lang="en-US">Mortgage loan carrying amount</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfRealEstatePropertiesHeldForSale" xlink:label="cli_NumberOfRealEstatePropertiesHeldForSale" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfRealEstatePropertiesHeldForSale" xlink:to="cli_NumberOfRealEstatePropertiesHeldForSale_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfRealEstatePropertiesHeldForSale_lbl" xml:lang="en-US">Number Of Real Estate Properties Held For Sale</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfRealEstatePropertiesHeldForSale_lbl" xml:lang="en-US">Number Of Real Estate Properties Held For Sale</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfRealEstatePropertiesHeldForSale_lbl" xml:lang="en-US">Number of properties held for sale</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnrealizedGainLossOnInvestments" xlink:label="us-gaap_UnrealizedGainLossOnInvestments" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrealizedGainLossOnInvestments" xlink:to="us-gaap_UnrealizedGainLossOnInvestments_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnrealizedGainLossOnInvestments_lbl" xml:lang="en-US">Unrealized Gain (Loss) on Investments</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_UnrealizedGainLossOnInvestments_lbl" xml:lang="en-US">Unrealized losses on rental properties held for sale</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EstimatedProceedsFromSaleOfRealEstateHeldForInvestment" xlink:label="cli_EstimatedProceedsFromSaleOfRealEstateHeldForInvestment" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EstimatedProceedsFromSaleOfRealEstateHeldForInvestment" xlink:to="cli_EstimatedProceedsFromSaleOfRealEstateHeldForInvestment_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EstimatedProceedsFromSaleOfRealEstateHeldForInvestment_lbl" xml:lang="en-US">Estimated Proceeds From Sale Of Real Estate Held For Investment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EstimatedProceedsFromSaleOfRealEstateHeldForInvestment_lbl" xml:lang="en-US">Estimated Proceeds From Sale Of Real Estate Held For Investment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_EstimatedProceedsFromSaleOfRealEstateHeldForInvestment_lbl" xml:lang="en-US">Estimated expected sales proceeds</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AssetsHeldForSaleNotPartOfDisposalGroupDeferredChargesAndOtherAssets" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupDeferredChargesAndOtherAssets" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AssetsHeldForSaleNotPartOfDisposalGroupDeferredChargesAndOtherAssets" xlink:to="cli_AssetsHeldForSaleNotPartOfDisposalGroupDeferredChargesAndOtherAssets_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupDeferredChargesAndOtherAssets_lbl" xml:lang="en-US">Assets Held-for-sale, Not Part of Disposal Group, Deferred Charges And Other Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupDeferredChargesAndOtherAssets_lbl" xml:lang="en-US">Assets Held-for-sale, Not Part of Disposal Group, Deferred Charges And Other Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupDeferredChargesAndOtherAssets_lbl" xml:lang="en-US">Assets held for sale, Deferred charges and other assets</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AssetsHeldForSaleNotPartOfDisposalGroupDeferredRentReceivablesNet" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupDeferredRentReceivablesNet" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AssetsHeldForSaleNotPartOfDisposalGroupDeferredRentReceivablesNet" xlink:to="cli_AssetsHeldForSaleNotPartOfDisposalGroupDeferredRentReceivablesNet_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupDeferredRentReceivablesNet_lbl" xml:lang="en-US">Assets Held-for-sale, Not Part of Disposal Group, Deferred Rent Receivables, Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupDeferredRentReceivablesNet_lbl" xml:lang="en-US">Assets Held-for-sale, Not Part of Disposal Group, Deferred Rent Receivables, Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupDeferredRentReceivablesNet_lbl" xml:lang="en-US">Assets held for sale, Unbilled rents receivable, net</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AssetsHeldForSaleNotPartOfDisposalGroupAccountsPayableAccruedExpensesAndOtherLiabilities" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupAccountsPayableAccruedExpensesAndOtherLiabilities" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AssetsHeldForSaleNotPartOfDisposalGroupAccountsPayableAccruedExpensesAndOtherLiabilities" xlink:to="cli_AssetsHeldForSaleNotPartOfDisposalGroupAccountsPayableAccruedExpensesAndOtherLiabilities_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupAccountsPayableAccruedExpensesAndOtherLiabilities_lbl" xml:lang="en-US">Assets Held-for-sale, Not Part of Disposal Group, Accounts Payable, Accrued Expenses And Other Liabilities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupAccountsPayableAccruedExpensesAndOtherLiabilities_lbl" xml:lang="en-US">Assets Held-for-sale, Not Part of Disposal Group, Accounts Payable, Accrued Expenses And Other Liabilities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupAccountsPayableAccruedExpensesAndOtherLiabilities_lbl" xml:lang="en-US">Assets held for sale, Accounts payable, accrued expenses and other liabilities</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AssetsHeldForSaleNotPartOfDisposalGroupAdvanceRentAndSecurityDeposits" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupAdvanceRentAndSecurityDeposits" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AssetsHeldForSaleNotPartOfDisposalGroupAdvanceRentAndSecurityDeposits" xlink:to="cli_AssetsHeldForSaleNotPartOfDisposalGroupAdvanceRentAndSecurityDeposits_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupAdvanceRentAndSecurityDeposits_lbl" xml:lang="en-US">Assets Held-for-sale, Not Part of Disposal Group, Advance Rent And Security Deposits</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupAdvanceRentAndSecurityDeposits_lbl" xml:lang="en-US">Assets Held-for-sale, Not Part of Disposal Group, Advance Rent And Security Deposits</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupAdvanceRentAndSecurityDeposits_lbl" xml:lang="en-US">Assets held for sale, Rents received in advance and security deposits</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AssetsHeldForSaleNotPartOfDisposalGroupExpectedAssetToBeWrittenOff" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupExpectedAssetToBeWrittenOff" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AssetsHeldForSaleNotPartOfDisposalGroupExpectedAssetToBeWrittenOff" xlink:to="cli_AssetsHeldForSaleNotPartOfDisposalGroupExpectedAssetToBeWrittenOff_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupExpectedAssetToBeWrittenOff_lbl" xml:lang="en-US">Assets Held-for-sale, Not Part of Disposal Group, Expected Asset To Be Written Off</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupExpectedAssetToBeWrittenOff_lbl" xml:lang="en-US">Assets Held-for-sale, Not Part of Disposal Group, Expected Asset To Be Written Off</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AssetsHeldForSaleNotPartOfDisposalGroupExpectedAssetToBeWrittenOff_lbl" xml:lang="en-US">Expected assets to be written off</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DisposalGroupIncludingDiscontinuedOperationLiabilitiesExpectedAssetToBeWrittenOff" xlink:label="cli_DisposalGroupIncludingDiscontinuedOperationLiabilitiesExpectedAssetToBeWrittenOff" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DisposalGroupIncludingDiscontinuedOperationLiabilitiesExpectedAssetToBeWrittenOff" xlink:to="cli_DisposalGroupIncludingDiscontinuedOperationLiabilitiesExpectedAssetToBeWrittenOff_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DisposalGroupIncludingDiscontinuedOperationLiabilitiesExpectedAssetToBeWrittenOff_lbl" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Liabilities, Expected Asset To Be Written Off</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DisposalGroupIncludingDiscontinuedOperationLiabilitiesExpectedAssetToBeWrittenOff_lbl" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Liabilities, Expected Asset To Be Written Off</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DisposalGroupIncludingDiscontinuedOperationLiabilitiesExpectedAssetToBeWrittenOff_lbl" xml:lang="en-US">Expected liabilities to be written off</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromSaleOfRealEstateHeldforinvestment" xlink:label="us-gaap_ProceedsFromSaleOfRealEstateHeldforinvestment" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromSaleOfRealEstateHeldforinvestment" xlink:to="us-gaap_ProceedsFromSaleOfRealEstateHeldforinvestment_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromSaleOfRealEstateHeldforinvestment_lbl" xml:lang="en-US">Proceeds from Sale of Real Estate Held-for-investment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromSaleOfRealEstateHeldforinvestment_lbl" xml:lang="en-US">Net Sales Proceeds</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ProceedsFromSaleOfRealEstateHeldforinvestment_lbl" xml:lang="en-US">Sales proceeds</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfRealEstatePropertiesNotExpectedToRecoverFromEstimatedNetSalesProceeds" xlink:label="cli_NumberOfRealEstatePropertiesNotExpectedToRecoverFromEstimatedNetSalesProceeds" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfRealEstatePropertiesNotExpectedToRecoverFromEstimatedNetSalesProceeds" xlink:to="cli_NumberOfRealEstatePropertiesNotExpectedToRecoverFromEstimatedNetSalesProceeds_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfRealEstatePropertiesNotExpectedToRecoverFromEstimatedNetSalesProceeds_lbl" xml:lang="en-US">Number Of Real Estate Properties, Not Expected To Recover From Estimated Net Sales Proceeds</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfRealEstatePropertiesNotExpectedToRecoverFromEstimatedNetSalesProceeds_lbl" xml:lang="en-US">Number Of Real Estate Properties, Not Expected To Recover From Estimated Net Sales Proceeds</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfRealEstatePropertiesNotExpectedToRecoverFromEstimatedNetSalesProceeds_lbl" xml:lang="en-US">Number of properties not epected to recover from estimated net sales proceeds</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfBuildingsOnPropertiesSold" xlink:label="cli_NumberOfBuildingsOnPropertiesSold" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfBuildingsOnPropertiesSold" xlink:to="cli_NumberOfBuildingsOnPropertiesSold_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfBuildingsOnPropertiesSold_lbl" xml:lang="en-US">Number Of Buildings On Properties Sold</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfBuildingsOnPropertiesSold_lbl" xml:lang="en-US">Number of buildings on properties sold</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfBuildingsOnPropertiesSold_lbl" xml:lang="en-US">Number of Buildings, Disposed</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_NumberOfBuildingsOnPropertiesSold_lbl" xml:lang="en-US">Number of properties sold</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfPreferredUnitsTable" xlink:label="us-gaap_ScheduleOfPreferredUnitsTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfPreferredUnitsTable" xlink:to="us-gaap_ScheduleOfPreferredUnitsTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfPreferredUnitsTable_lbl" xml:lang="en-US">Schedule of Preferred Units [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PreferredUnitsLineItems" xlink:label="us-gaap_PreferredUnitsLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredUnitsLineItems" xlink:to="us-gaap_PreferredUnitsLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredUnitsLineItems_lbl" xml:lang="en-US">Preferred Units [Line Items]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ContributionValueEquityUnitsLimitedPartnershipInterest" xlink:label="cli_ContributionValueEquityUnitsLimitedPartnershipInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ContributionValueEquityUnitsLimitedPartnershipInterest" xlink:to="cli_ContributionValueEquityUnitsLimitedPartnershipInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ContributionValueEquityUnitsLimitedPartnershipInterest_lbl" xml:lang="en-US">Contribution Value Equity Units Limited Partnership Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ContributionValueEquityUnitsLimitedPartnershipInterest_lbl" xml:lang="en-US">Contribution Value Equity Units Limited Partnership Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ContributionValueEquityUnitsLimitedPartnershipInterest_lbl" xml:lang="en-US">Contributed amount to obtain equity units</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets" xlink:to="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets_lbl" xml:lang="en-US">Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets_lbl" xml:lang="en-US">Total assets</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_IncrementalContributionValueEquityUnitsLimitedPartnershipInterest" xlink:label="cli_IncrementalContributionValueEquityUnitsLimitedPartnershipInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_IncrementalContributionValueEquityUnitsLimitedPartnershipInterest" xlink:to="cli_IncrementalContributionValueEquityUnitsLimitedPartnershipInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_IncrementalContributionValueEquityUnitsLimitedPartnershipInterest_lbl" xml:lang="en-US">Incremental Contribution Value Equity Units Limited Partnership Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_IncrementalContributionValueEquityUnitsLimitedPartnershipInterest_lbl" xml:lang="en-US">Incremental Contribution Value Equity Units Limited Partnership Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_IncrementalContributionValueEquityUnitsLimitedPartnershipInterest_lbl" xml:lang="en-US">Incremental closing payments, Limited Partnership interest</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt" xlink:to="cli_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Secured Debt</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Secured Debt</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt_lbl" xml:lang="en-US">Mortgages and loans payable</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EquityMethodInvestmentSummarizedFinancialInformationOtherLiabilities" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationOtherLiabilities" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EquityMethodInvestmentSummarizedFinancialInformationOtherLiabilities" xlink:to="cli_EquityMethodInvestmentSummarizedFinancialInformationOtherLiabilities_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationOtherLiabilities_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Other Liabilities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationOtherLiabilities_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Other Liabilities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationOtherLiabilities_lbl" xml:lang="en-US">Other liabilities</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PariPassuInterestPercent" xlink:label="cli_PariPassuInterestPercent" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PariPassuInterestPercent" xlink:to="cli_PariPassuInterestPercent_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PariPassuInterestPercent_lbl" xml:lang="en-US">Pari Passu Interest, Percent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PariPassuInterestPercent_lbl" xml:lang="en-US">Pari Passu Interest, Percent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PariPassuInterestPercent_lbl" xml:lang="en-US">Percent of pari passu interest</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PreferredUnitValue" xlink:label="cli_PreferredUnitValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PreferredUnitValue" xlink:to="cli_PreferredUnitValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PreferredUnitValue_lbl" xml:lang="en-US">Value of the preferred units acquired.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PreferredUnitValue_lbl" xml:lang="en-US">Preferred Unit Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PreferredUnitValue_lbl" xml:lang="en-US">Preferred unit in operating partnership</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ProceedsFromSaleOfRealEstateHeldForInvestmentHeldByQualifiedIntermediary" xlink:label="cli_ProceedsFromSaleOfRealEstateHeldForInvestmentHeldByQualifiedIntermediary" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ProceedsFromSaleOfRealEstateHeldForInvestmentHeldByQualifiedIntermediary" xlink:to="cli_ProceedsFromSaleOfRealEstateHeldForInvestmentHeldByQualifiedIntermediary_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ProceedsFromSaleOfRealEstateHeldForInvestmentHeldByQualifiedIntermediary_lbl" xml:lang="en-US">Proceeds From Sale Of Real Estate Held For Investment, Held By A Qualified Intermediary</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ProceedsFromSaleOfRealEstateHeldForInvestmentHeldByQualifiedIntermediary_lbl" xml:lang="en-US">Proceeds From Sale Of Real Estate Held For Investment, Held By A Qualified Intermediary</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ProceedsFromSaleOfRealEstateHeldForInvestmentHeldByQualifiedIntermediary_lbl" xml:lang="en-US">Net sales proceeds held by qualified intermediary</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebt" xlink:label="us-gaap_LongTermDebt" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebt" xlink:to="us-gaap_LongTermDebt_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebt_lbl" xml:lang="en-US">Long-term Debt</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:label="us-gaap_LongTermDebt_lbl" xml:lang="en-US">Debt</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebt_lbl" xml:lang="en-US">Total indebtedness</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LongTermDebt_lbl" xml:lang="en-US">Total senior unsecured notes, net</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_lbl" xml:lang="en-US">Schedule of Business Acquisitions, by Acquisition [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionAxis_lbl" xml:lang="en-US">Business Acquisition [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_lbl" xml:lang="en-US">Business Acquisition Acquiree [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_lbl" xml:lang="en-US">Business Acquisition, Acquiree [Domain]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ElevenMartineAvenueWhitePlainsNewYorkMember" xlink:label="cli_ElevenMartineAvenueWhitePlainsNewYorkMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ElevenMartineAvenueWhitePlainsNewYorkMember" xlink:to="cli_ElevenMartineAvenueWhitePlainsNewYorkMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ElevenMartineAvenueWhitePlainsNewYorkMember_lbl" xml:lang="en-US">Eleven Martine Avenue, White Plains, New York [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ElevenMartineAvenueWhitePlainsNewYorkMember_lbl" xml:lang="en-US">Eleven Martine Avenue White Plains New York [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ElevenMartineAvenueWhitePlainsNewYorkMember_lbl" xml:lang="en-US">11 Martine Avenue [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeTwentyThreeTwentyOneUniversityAvenueNewarkNewJerseyMember" xlink:label="cli_ThreeTwentyThreeTwentyOneUniversityAvenueNewarkNewJerseyMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeTwentyThreeTwentyOneUniversityAvenueNewarkNewJerseyMember" xlink:to="cli_ThreeTwentyThreeTwentyOneUniversityAvenueNewarkNewJerseyMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeTwentyThreeTwentyOneUniversityAvenueNewarkNewJerseyMember_lbl" xml:lang="en-US">Three Twenty, Three Twenty One University Avenue, Newark, New Jersey [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeTwentyThreeTwentyOneUniversityAvenueNewarkNewJerseyMember_lbl" xml:lang="en-US">Three Twenty Three Twenty One University Avenue Newark New Jersey [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeTwentyThreeTwentyOneUniversityAvenueNewarkNewJerseyMember_lbl" xml:lang="en-US">320, 321 University Avenue [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredOneWoodAvenueSouthEdisonNewJerseyMember" xlink:label="cli_OneHundredOneWoodAvenueSouthEdisonNewJerseyMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredOneWoodAvenueSouthEdisonNewJerseyMember" xlink:to="cli_OneHundredOneWoodAvenueSouthEdisonNewJerseyMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredOneWoodAvenueSouthEdisonNewJerseyMember_lbl" xml:lang="en-US">One Hundred One Wood Avenue South, Edison, New Jersey [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredOneWoodAvenueSouthEdisonNewJerseyMember_lbl" xml:lang="en-US">One Hundred One Wood Avenue South Edison New Jersey [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredOneWoodAvenueSouthEdisonNewJerseyMember_lbl" xml:lang="en-US">101 Wood Avenue South [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredElevenRiverStreetHobokenNewJerseyMember" xlink:label="cli_OneHundredElevenRiverStreetHobokenNewJerseyMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredElevenRiverStreetHobokenNewJerseyMember" xlink:to="cli_OneHundredElevenRiverStreetHobokenNewJerseyMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredElevenRiverStreetHobokenNewJerseyMember_lbl" xml:lang="en-US">One Hundred Eleven River Street, Hoboken, New Jersey [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredElevenRiverStreetHobokenNewJerseyMember_lbl" xml:lang="en-US">One Hundred Eleven River Street Hoboken New Jersey [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredElevenRiverStreetHobokenNewJerseyMember_lbl" xml:lang="en-US">111 River Street [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionLineItems_lbl" xml:lang="en-US">Business Acquisition [Line Items]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfPropertiesAcquired" xlink:label="cli_NumberOfPropertiesAcquired" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfPropertiesAcquired" xlink:to="cli_NumberOfPropertiesAcquired_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfPropertiesAcquired_lbl" xml:lang="en-US">Number Of Properties Acquired</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfPropertiesAcquired_lbl" xml:lang="en-US">Number Of Properties Acquired</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfPropertiesAcquired_lbl" xml:lang="en-US">Number of Buildings, Acquired</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AreaOfRealEstatePropertyAcquired" xlink:label="cli_AreaOfRealEstatePropertyAcquired" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AreaOfRealEstatePropertyAcquired" xlink:to="cli_AreaOfRealEstatePropertyAcquired_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AreaOfRealEstatePropertyAcquired_lbl" xml:lang="en-US">Area Of Real Estate Property Acquired</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AreaOfRealEstatePropertyAcquired_lbl" xml:lang="en-US">Area Of Real Estate Property Acquired</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AreaOfRealEstatePropertyAcquired_lbl" xml:lang="en-US">Rentable Square Feet, Acquired</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationConsiderationTransferred1" xlink:to="us-gaap_BusinessCombinationConsiderationTransferred1_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1_lbl" xml:lang="en-US">Business Combination, Consideration Transferred</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1_lbl" xml:lang="en-US">Acquisition Cost</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfUnitsOnPropertyAcquired" xlink:label="cli_NumberOfUnitsOnPropertyAcquired" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfUnitsOnPropertyAcquired" xlink:to="cli_NumberOfUnitsOnPropertyAcquired_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfUnitsOnPropertyAcquired_lbl" xml:lang="en-US">Number Of Units On Property Acquired</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfUnitsOnPropertyAcquired_lbl" xml:lang="en-US">Number Of Units On Property Acquired</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_NumberOfUnitsOnPropertyAcquired_lbl" xml:lang="en-US">Number of apartment units</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="us-gaap_DebtInstrumentCarryingAmount" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentCarryingAmount" xlink:to="us-gaap_DebtInstrumentCarryingAmount_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl" xml:lang="en-US">Long-term Debt, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl" xml:lang="en-US">Loan balance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl" xml:lang="en-US">Principal balance outstanding</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand_lbl" xml:lang="en-US">Business Acquisition, Purchase Price Allocation, Land</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand_lbl" xml:lang="en-US">Land and leasehold interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand_lbl" xml:lang="en-US">Land and Leasehold Interests</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBuildings" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBuildings" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBuildings" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBuildings_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBuildings_lbl" xml:lang="en-US">Business Acquisition, Purchase Price Allocation, Buildings</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBuildings_lbl" xml:lang="en-US">Buildings and improvements and other assets</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAboveMarketLeases" xlink:label="cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAboveMarketLeases" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAboveMarketLeases" xlink:to="cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAboveMarketLeases_lbl" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInPlaceLeases_lbl" xml:lang="en-US">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, In Place Leases</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInPlaceLeases_lbl" xml:lang="en-US">In-place lease values</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBelowMarketLeases_lbl" xml:lang="en-US">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Below Market Leases</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBelowMarketLeases_lbl" xml:lang="en-US">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Below Market Leases</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_lbl" xml:lang="en-US">Finite-Lived Intangible Asset, Useful Life</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_lbl" xml:lang="en-US">Amortization period</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RealEstateDevelopmentCostsIncurred" xlink:to="cli_RealEstateDevelopmentCostsIncurred_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RealEstateDevelopmentCostsIncurred_lbl" xml:lang="en-US">Real Estate Development Costs Incurred</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RealEstateDevelopmentCostsIncurred_lbl" xml:lang="en-US">Real Estate Development Costs Incurred</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RealEstateDevelopmentCostsIncurred_lbl" xml:lang="en-US">Development Costs Incurred by Company</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DevelopmentCostsExpectedCosts" xlink:label="cli_DevelopmentCostsExpectedCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DevelopmentCostsExpectedCosts" xlink:to="cli_DevelopmentCostsExpectedCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DevelopmentCostsExpectedCosts_lbl" xml:lang="en-US">Development Costs, Expected Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DevelopmentCostsExpectedCosts_lbl" xml:lang="en-US">Development Costs, Expected Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DevelopmentCostsExpectedCosts_lbl" xml:lang="en-US">Expected costs</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEquipment" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEquipment" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEquipment" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEquipment_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEquipment_lbl" xml:lang="en-US">Business Acquisition, Purchase Price Allocation, Equipment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEquipment_lbl" xml:lang="en-US">Furniture, fixtures and equipment</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_lbl" xml:lang="en-US">Business Acquisition, Purchase Price Allocation, Liabilities Assumed</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_lbl" xml:lang="en-US">Less: Debt assumed at fair value</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_lbl" xml:lang="en-US">Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:to="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_lbl" xml:lang="en-US">Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AreaOfRealEstatePropertySold" xlink:label="cli_AreaOfRealEstatePropertySold" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AreaOfRealEstatePropertySold" xlink:to="cli_AreaOfRealEstatePropertySold_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AreaOfRealEstatePropertySold_lbl" xml:lang="en-US">Area Of Real Estate Property Sold</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AreaOfRealEstatePropertySold_lbl" xml:lang="en-US">Area Of Real Estate Property Sold</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AreaOfRealEstatePropertySold_lbl" xml:lang="en-US">Rentable Square Feet, Disposed</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNetValue" xlink:label="cli_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNetValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNetValue" xlink:to="cli_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNetValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNetValue_lbl" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Property, Plant and Equipment, Net Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNetValue_lbl" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Property, Plant and Equipment, Net Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNetValue_lbl" xml:lang="en-US">Net Carrying Value</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GainLossOnDispositionOfRealEstateDiscontinuedOperations" xlink:label="us-gaap_GainLossOnDispositionOfRealEstateDiscontinuedOperations" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnDispositionOfRealEstateDiscontinuedOperations" xlink:to="us-gaap_GainLossOnDispositionOfRealEstateDiscontinuedOperations_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GainLossOnDispositionOfRealEstateDiscontinuedOperations_lbl" xml:lang="en-US">Gain (Loss) on Disposition of Real Estate, Discontinued Operations</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_GainLossOnDispositionOfRealEstateDiscontinuedOperations_lbl" xml:lang="en-US">Realized Gain (loss)/Unrealized Loss, net</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_InternalRateOfReturn" xlink:label="cli_InternalRateOfReturn" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_InternalRateOfReturn" xlink:to="cli_InternalRateOfReturn_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_InternalRateOfReturn_lbl" xml:lang="en-US">Internal Rate of Return</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_InternalRateOfReturn_lbl" xml:lang="en-US">Internal rate of return</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_InternalRateOfReturn_lbl" xml:lang="en-US">Internal rate of return</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgageLoansOnRealEstateNewMortgageLoans" xlink:label="us-gaap_MortgageLoansOnRealEstateNewMortgageLoans" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MortgageLoansOnRealEstateNewMortgageLoans" xlink:to="us-gaap_MortgageLoansOnRealEstateNewMortgageLoans_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageLoansOnRealEstateNewMortgageLoans_lbl" xml:lang="en-US">Mortgage Loans on Real Estate, New Mortgage Loans</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_MortgageLoansOnRealEstateNewMortgageLoans_lbl" xml:lang="en-US">New mortgage loan</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_GainLossOnDispositionOfRealEstateDiscontinuedOperationsNetOfUnrealizedGainLosses" xlink:label="cli_GainLossOnDispositionOfRealEstateDiscontinuedOperationsNetOfUnrealizedGainLosses" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_GainLossOnDispositionOfRealEstateDiscontinuedOperationsNetOfUnrealizedGainLosses" xlink:to="cli_GainLossOnDispositionOfRealEstateDiscontinuedOperationsNetOfUnrealizedGainLosses_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_GainLossOnDispositionOfRealEstateDiscontinuedOperationsNetOfUnrealizedGainLosses_lbl" xml:lang="en-US">Gain Loss On Disposition Of Real Estate Discontinued Operations, Net Of Unrealized Gain Losses</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_GainLossOnDispositionOfRealEstateDiscontinuedOperationsNetOfUnrealizedGainLosses_lbl" xml:lang="en-US">Gain Loss On Disposition Of Real Estate Discontinued Operations, Net Of Unrealized Gain Losses</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_GainLossOnDispositionOfRealEstateDiscontinuedOperationsNetOfUnrealizedGainLosses_lbl" xml:lang="en-US">Totals</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentMaturityDate" xlink:label="us-gaap_DebtInstrumentMaturityDate" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentMaturityDate" xlink:to="us-gaap_DebtInstrumentMaturityDate_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl" xml:lang="en-US">Mortgage loan, maturity date</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl" xml:lang="en-US">Loan maturity date</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl" xml:lang="en-US">Maturity date of the senior unsecured notes</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtInstrumentNumberOfExtensionOptions" xlink:label="cli_DebtInstrumentNumberOfExtensionOptions" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtInstrumentNumberOfExtensionOptions" xlink:to="cli_DebtInstrumentNumberOfExtensionOptions_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtInstrumentNumberOfExtensionOptions_lbl" xml:lang="en-US">Debt Instrument, Number Of Extension Options</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtInstrumentNumberOfExtensionOptions_lbl" xml:lang="en-US">Debt Instrument, Number Of Extension Options</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DebtInstrumentNumberOfExtensionOptions_lbl" xml:lang="en-US">Number of extension options</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtInstrumentExtensionPeriod" xlink:label="cli_DebtInstrumentExtensionPeriod" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtInstrumentExtensionPeriod" xlink:to="cli_DebtInstrumentExtensionPeriod_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtInstrumentExtensionPeriod_lbl" xml:lang="en-US">Debt Instrument Extension Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtInstrumentExtensionPeriod_lbl" xml:lang="en-US">Debt Instrument Extension Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DebtInstrumentExtensionPeriod_lbl" xml:lang="en-US">Loan extension period</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xml:lang="en-US">Property Debt, Interest Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xml:lang="en-US">Interest rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xml:lang="en-US">Interest rate of senior unsecured notes</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NotesReceivableGross" xlink:label="us-gaap_NotesReceivableGross" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesReceivableGross" xlink:to="us-gaap_NotesReceivableGross_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NotesReceivableGross_lbl" xml:lang="en-US">Financing Receivable, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NotesReceivableGross_lbl" xml:lang="en-US">Notes receivable</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LandAvailableForSale" xlink:label="us-gaap_LandAvailableForSale" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LandAvailableForSale" xlink:to="us-gaap_LandAvailableForSale_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LandAvailableForSale_lbl" xml:lang="en-US">Land Available-for-sale</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LandAvailableForSale_lbl" xml:lang="en-US">Land</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_BuildingsAndImprovementsAvailableForSale" xlink:label="cli_BuildingsAndImprovementsAvailableForSale" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_BuildingsAndImprovementsAvailableForSale" xlink:to="cli_BuildingsAndImprovementsAvailableForSale_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_BuildingsAndImprovementsAvailableForSale_lbl" xml:lang="en-US">Buildings And Improvements Available For Sale</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_BuildingsAndImprovementsAvailableForSale_lbl" xml:lang="en-US">Buildings And Improvements Available For Sale</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_BuildingsAndImprovementsAvailableForSale_lbl" xml:lang="en-US">Buildings and improvements</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_UnrealizedGainLossOnInvestmentsHeldForSale" xlink:label="cli_UnrealizedGainLossOnInvestmentsHeldForSale" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_UnrealizedGainLossOnInvestmentsHeldForSale" xlink:to="cli_UnrealizedGainLossOnInvestmentsHeldForSale_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_UnrealizedGainLossOnInvestmentsHeldForSale_lbl" xml:lang="en-US">Unrealized Gain Loss On Investments Held For Sale</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_UnrealizedGainLossOnInvestmentsHeldForSale_lbl" xml:lang="en-US">Unrealized Gain Loss On Investments Held For Sale</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_UnrealizedGainLossOnInvestmentsHeldForSale_lbl" xml:lang="en-US">Less: Unrealized losses on properties held for sale</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsTable" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentsTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEquityMethodInvestmentsTable" xlink:to="us-gaap_ScheduleOfEquityMethodInvestmentsTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentsTable_lbl" xml:lang="en-US">Schedule of Equity Method Investments [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:to="us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_lbl" xml:lang="en-US">Schedule of Equity Method Investment, Equity Method Investee, Name [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityMethodInvesteeNameDomain" xlink:label="us-gaap_EquityMethodInvesteeNameDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvesteeNameDomain" xlink:to="us-gaap_EquityMethodInvesteeNameDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvesteeNameDomain_lbl" xml:lang="en-US">Equity Method Investee Name [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EquityMethodInvesteeNameDomain_lbl" xml:lang="en-US">Equity Method Investee, Name [Domain]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SouthPierAtHarborsideMember" xlink:label="cli_SouthPierAtHarborsideMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SouthPierAtHarborsideMember" xlink:to="cli_SouthPierAtHarborsideMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SouthPierAtHarborsideMember_lbl" xml:lang="en-US">South Pier At Harborside [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SouthPierAtHarborsideMember_lbl" xml:lang="en-US">South Pier At Harborside [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SouthPierAtHarborsideMember_lbl" xml:lang="en-US">South Pier At Harborside [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis" xlink:label="us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis" xlink:to="us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_lbl" xml:lang="en-US">Variable Interest Entities [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ClassificationOfVariableInterestEntityDomain" xlink:label="us-gaap_ClassificationOfVariableInterestEntityDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassificationOfVariableInterestEntityDomain" xlink:to="us-gaap_ClassificationOfVariableInterestEntityDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ClassificationOfVariableInterestEntityDomain_lbl" xml:lang="en-US">Classification Of Variable Interest Entity [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ClassificationOfVariableInterestEntityDomain_lbl" xml:lang="en-US">Variable Interest Entity, Classification [Domain]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember" xlink:label="us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember" xlink:to="us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember_lbl" xml:lang="en-US">Variable Interest Entity Not Primary Beneficiary [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember_lbl" xml:lang="en-US">Variable Interest Entity [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_UnconsolidatedJointVentureRetailBuildingsMember" xlink:label="cli_UnconsolidatedJointVentureRetailBuildingsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_UnconsolidatedJointVentureRetailBuildingsMember" xlink:to="cli_UnconsolidatedJointVentureRetailBuildingsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_UnconsolidatedJointVentureRetailBuildingsMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Retail Buildings [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_UnconsolidatedJointVentureRetailBuildingsMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Retail Buildings [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_UnconsolidatedJointVentureRetailBuildingsMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Retail Buildings [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_UnconsolidatedJointVentureHotelMember" xlink:label="cli_UnconsolidatedJointVentureHotelMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_UnconsolidatedJointVentureHotelMember" xlink:to="cli_UnconsolidatedJointVentureHotelMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_UnconsolidatedJointVentureHotelMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Hotel [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_UnconsolidatedJointVentureHotelMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Hotel [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_UnconsolidatedJointVentureHotelMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Hotel [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_UnconsolidatedJointVentureDevelopmentProjectsMember" xlink:label="cli_UnconsolidatedJointVentureDevelopmentProjectsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_UnconsolidatedJointVentureDevelopmentProjectsMember" xlink:to="cli_UnconsolidatedJointVentureDevelopmentProjectsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_UnconsolidatedJointVentureDevelopmentProjectsMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Development Projects [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_UnconsolidatedJointVentureDevelopmentProjectsMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Development Projects [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_UnconsolidatedJointVentureDevelopmentProjectsMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Development Projects [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_UnconsolidatedJointVentureLandParcelsMember" xlink:label="cli_UnconsolidatedJointVentureLandParcelsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_UnconsolidatedJointVentureLandParcelsMember" xlink:to="cli_UnconsolidatedJointVentureLandParcelsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_UnconsolidatedJointVentureLandParcelsMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Land Parcels [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_UnconsolidatedJointVentureLandParcelsMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Land Parcels [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_UnconsolidatedJointVentureLandParcelsMember_lbl" xml:lang="en-US">Unconsolidated Joint Venture Land Parcels [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_UnconsolidatedJointVenturesMember" xlink:label="cli_UnconsolidatedJointVenturesMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_UnconsolidatedJointVenturesMember" xlink:to="cli_UnconsolidatedJointVenturesMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_UnconsolidatedJointVenturesMember_lbl" xml:lang="en-US">Unconsolidated Joint Ventures [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_UnconsolidatedJointVenturesMember_lbl" xml:lang="en-US">Unconsolidated Joint Ventures [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_UnconsolidatedJointVenturesMember_lbl" xml:lang="en-US">Unconsolidated Joint Ventures [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsLineItems" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentsLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEquityMethodInvestmentsLineItems" xlink:to="us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_lbl" xml:lang="en-US">Schedule of Equity Method Investments [Line Items]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AreaOfMixedUseProperty" xlink:label="cli_AreaOfMixedUseProperty" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AreaOfMixedUseProperty" xlink:to="cli_AreaOfMixedUseProperty_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AreaOfMixedUseProperty_lbl" xml:lang="en-US">Area Of Mixed Use Property</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AreaOfMixedUseProperty_lbl" xml:lang="en-US">Area Of Mixed Use Property</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AreaOfMixedUseProperty_lbl" xml:lang="en-US">Area of mixed use project (in square feet)</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xml:lang="en-US">Maximum borrowing capacity</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xml:lang="en-US">Borrowing capacity under the credit facility</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ManagementLeasingDevelopmentAndOtherServicesFees" xlink:label="cli_ManagementLeasingDevelopmentAndOtherServicesFees" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ManagementLeasingDevelopmentAndOtherServicesFees" xlink:to="cli_ManagementLeasingDevelopmentAndOtherServicesFees_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ManagementLeasingDevelopmentAndOtherServicesFees_lbl" xml:lang="en-US">Management, Leasing, Development And Other Services Fees</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ManagementLeasingDevelopmentAndOtherServicesFees_lbl" xml:lang="en-US">Management, Leasing, Development And Other Services Fees</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ManagementLeasingDevelopmentAndOtherServicesFees_lbl" xml:lang="en-US">Management, leasing, development and other services fees</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DueFromJointVentures" xlink:label="us-gaap_DueFromJointVentures" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DueFromJointVentures" xlink:to="us-gaap_DueFromJointVentures_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DueFromJointVentures_lbl" xml:lang="en-US">Due from Joint Ventures</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DueFromJointVentures_lbl" xml:lang="en-US">Accounts receivable due from unconsolidated joint ventures</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfVariableInterestEntities" xlink:label="cli_NumberOfVariableInterestEntities" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfVariableInterestEntities" xlink:to="cli_NumberOfVariableInterestEntities_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfVariableInterestEntities_lbl" xml:lang="en-US">Number Of Variable Interest Entities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfVariableInterestEntities_lbl" xml:lang="en-US">Number Of Variable Interest Entities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfVariableInterestEntities_lbl" xml:lang="en-US">Number of VIEs</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount" xlink:label="us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount" xlink:to="us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount_lbl" xml:lang="en-US">Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount_lbl" xml:lang="en-US">Maximum exposure to loss</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_VariableInterestEntityEntityEstimatedFutureFundingCommitments" xlink:label="cli_VariableInterestEntityEntityEstimatedFutureFundingCommitments" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_VariableInterestEntityEntityEstimatedFutureFundingCommitments" xlink:to="cli_VariableInterestEntityEntityEstimatedFutureFundingCommitments_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_VariableInterestEntityEntityEstimatedFutureFundingCommitments_lbl" xml:lang="en-US">Variable Interest Entity, Entity Estimated Future Funding Commitments</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_VariableInterestEntityEntityEstimatedFutureFundingCommitments_lbl" xml:lang="en-US">Variable Interest Entity, Entity Estimated Future Funding Commitments</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_VariableInterestEntityEntityEstimatedFutureFundingCommitments_lbl" xml:lang="en-US">Estimated future funding commitments</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis" xlink:to="us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_lbl" xml:lang="en-US">Name of Property [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain" xlink:to="us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_lbl" xml:lang="en-US">Real Estate And Accumulated Depreciation Name Of Property [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_lbl" xml:lang="en-US">Name of Property [Domain]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ShopsAtFortyParkPropertyMember" xlink:label="cli_ShopsAtFortyParkPropertyMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ShopsAtFortyParkPropertyMember" xlink:to="cli_ShopsAtFortyParkPropertyMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ShopsAtFortyParkPropertyMember_lbl" xml:lang="en-US">The Shops At Forty Park Property [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ShopsAtFortyParkPropertyMember_lbl" xml:lang="en-US">Shops At Forty Park Property [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ShopsAtFortyParkPropertyMember_lbl" xml:lang="en-US">The Shops At 40 Park Property [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LoftsAtFortyParkPropertyMember" xlink:label="cli_LoftsAtFortyParkPropertyMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LoftsAtFortyParkPropertyMember" xlink:to="cli_LoftsAtFortyParkPropertyMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LoftsAtFortyParkPropertyMember_lbl" xml:lang="en-US">Lofts At 40 Park Property [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LoftsAtFortyParkPropertyMember_lbl" xml:lang="en-US">Lofts At Forty Park Property [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_LoftsAtFortyParkPropertyMember_lbl" xml:lang="en-US">Lofts At 40 Park Property [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MetropolitanPropertyMember" xlink:label="cli_MetropolitanPropertyMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MetropolitanPropertyMember" xlink:to="cli_MetropolitanPropertyMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MetropolitanPropertyMember_lbl" xml:lang="en-US">Metropolitan Property [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MetropolitanPropertyMember_lbl" xml:lang="en-US">Metropolitan Property [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MetropolitanPropertyMember_lbl" xml:lang="en-US">Metropolitan Property [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RedBankCorporatePlazaLLCMember" xlink:label="cli_RedBankCorporatePlazaLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RedBankCorporatePlazaLLCMember" xlink:to="cli_RedBankCorporatePlazaLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RedBankCorporatePlazaLLCMember_lbl" xml:lang="en-US">Red Bank Corporate Plaza, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RedBankCorporatePlazaLLCMember_lbl" xml:lang="en-US">Red Bank Corporate Plaza L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RedBankCorporatePlazaLLCMember_lbl" xml:lang="en-US">Red Bank Corporate Plaza, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwelveVreelandAssociatesLLCMember" xlink:label="cli_TwelveVreelandAssociatesLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwelveVreelandAssociatesLLCMember" xlink:to="cli_TwelveVreelandAssociatesLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwelveVreelandAssociatesLLCMember_lbl" xml:lang="en-US">12 Vreeland Associates, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwelveVreelandAssociatesLLCMember_lbl" xml:lang="en-US">Twelve Vreeland Associates L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwelveVreelandAssociatesLLCMember_lbl" xml:lang="en-US">12 Vreeland Associates, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MarbellaRoseGardenLLCMember" xlink:label="cli_MarbellaRoseGardenLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MarbellaRoseGardenLLCMember" xlink:to="cli_MarbellaRoseGardenLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MarbellaRoseGardenLLCMember_lbl" xml:lang="en-US">Marbella RoseGarden, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MarbellaRoseGardenLLCMember_lbl" xml:lang="en-US">Marbella Rose Garden L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MarbellaRoseGardenLLCMember_lbl" xml:lang="en-US">Marbella RoseGarden, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RoseGardenMonacoHoldingsLLCMember" xlink:label="cli_RoseGardenMonacoHoldingsLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RoseGardenMonacoHoldingsLLCMember" xlink:to="cli_RoseGardenMonacoHoldingsLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RoseGardenMonacoHoldingsLLCMember_lbl" xml:lang="en-US">RoseGarden Monaco Holdings, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RoseGardenMonacoHoldingsLLCMember_lbl" xml:lang="en-US">Rose Garden Monaco Holdings L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RoseGardenMonacoHoldingsLLCMember_lbl" xml:lang="en-US">RoseGarden Monaco Holdings, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RosewoodMorristownLLCMember" xlink:label="cli_RosewoodMorristownLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RosewoodMorristownLLCMember" xlink:to="cli_RosewoodMorristownLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RosewoodMorristownLLCMember_lbl" xml:lang="en-US">Rosewood Morristown, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RosewoodMorristownLLCMember_lbl" xml:lang="en-US">Rosewood Morristown L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RosewoodMorristownLLCMember_lbl" xml:lang="en-US">Rosewood Morristown, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RoselandNorthRetailLLCMember" xlink:label="cli_RoselandNorthRetailLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RoselandNorthRetailLLCMember" xlink:to="cli_RoselandNorthRetailLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RoselandNorthRetailLLCMember_lbl" xml:lang="en-US">Roseland/North Retail, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RoselandNorthRetailLLCMember_lbl" xml:lang="en-US">Roseland North Retail L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RoselandNorthRetailLLCMember_lbl" xml:lang="en-US">Roseland/North Retail, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_BNESAssociatesIIIMember" xlink:label="cli_BNESAssociatesIIIMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_BNESAssociatesIIIMember" xlink:to="cli_BNESAssociatesIIIMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_BNESAssociatesIIIMember_lbl" xml:lang="en-US">BNES Associates III [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_BNESAssociatesIIIMember_lbl" xml:lang="en-US">B N E S Associates I I I [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_BNESAssociatesIIIMember_lbl" xml:lang="en-US">BNES Associates III [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RoselandPortImperialPartnersLPMember" xlink:label="cli_RoselandPortImperialPartnersLPMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RoselandPortImperialPartnersLPMember" xlink:to="cli_RoselandPortImperialPartnersLPMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RoselandPortImperialPartnersLPMember_lbl" xml:lang="en-US">Roseland/Port Imperial Partners, L.P. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RoselandPortImperialPartnersLPMember_lbl" xml:lang="en-US">Roseland Port Imperial Partners L P [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RoselandPortImperialPartnersLPMember_lbl" xml:lang="en-US">Roseland/Port Imperial Partners, L.P. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RoseGardenMarbellaSouthLLCMember" xlink:label="cli_RoseGardenMarbellaSouthLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RoseGardenMarbellaSouthLLCMember" xlink:to="cli_RoseGardenMarbellaSouthLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RoseGardenMarbellaSouthLLCMember_lbl" xml:lang="en-US">RoseGarden Marbella South, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RoseGardenMarbellaSouthLLCMember_lbl" xml:lang="en-US">Rose Garden Marbella South L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RoseGardenMarbellaSouthLLCMember_lbl" xml:lang="en-US">RoseGarden Marbella South, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ElmajoUrbanRenewalAssociatesLLCMember" xlink:label="cli_ElmajoUrbanRenewalAssociatesLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ElmajoUrbanRenewalAssociatesLLCMember" xlink:to="cli_ElmajoUrbanRenewalAssociatesLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ElmajoUrbanRenewalAssociatesLLCMember_lbl" xml:lang="en-US">Elmajo Urban Renewal Associates, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ElmajoUrbanRenewalAssociatesLLCMember_lbl" xml:lang="en-US">Elmajo Urban Renewal Associates L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ElmajoUrbanRenewalAssociatesLLCMember_lbl" xml:lang="en-US">Elmajo Urban Renewal Associates, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EstuaryUrbanRenewalUnitBLLCMember" xlink:label="cli_EstuaryUrbanRenewalUnitBLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EstuaryUrbanRenewalUnitBLLCMember" xlink:to="cli_EstuaryUrbanRenewalUnitBLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EstuaryUrbanRenewalUnitBLLCMember_lbl" xml:lang="en-US">Estuary Urban Renewal Unit B, LLC [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EstuaryUrbanRenewalUnitBLLCMember_lbl" xml:lang="en-US">Estuary Urban Renewal Unit B L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_EstuaryUrbanRenewalUnitBLLCMember_lbl" xml:lang="en-US">Estuary Urban Renewal Unit B, LLC [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RiverparkAtHarrisonILLCMember" xlink:label="cli_RiverparkAtHarrisonILLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RiverparkAtHarrisonILLCMember" xlink:to="cli_RiverparkAtHarrisonILLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RiverparkAtHarrisonILLCMember_lbl" xml:lang="en-US">Riverpark At Harrison I, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RiverparkAtHarrisonILLCMember_lbl" xml:lang="en-US">Riverpark At Harrison I L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RiverparkAtHarrisonILLCMember_lbl" xml:lang="en-US">Riverpark At Harrison I, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RoseGardenMonacoLLCMember" xlink:label="cli_RoseGardenMonacoLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RoseGardenMonacoLLCMember" xlink:to="cli_RoseGardenMonacoLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RoseGardenMonacoLLCMember_lbl" xml:lang="en-US">RoseGarden Monaco, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RoseGardenMonacoLLCMember_lbl" xml:lang="en-US">Rose Garden Monaco L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RoseGardenMonacoLLCMember_lbl" xml:lang="en-US">RoseGarden Monaco, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_GrandJerseyWaterfrontUrbanRenewalAssociatesLLCMember" xlink:label="cli_GrandJerseyWaterfrontUrbanRenewalAssociatesLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_GrandJerseyWaterfrontUrbanRenewalAssociatesLLCMember" xlink:to="cli_GrandJerseyWaterfrontUrbanRenewalAssociatesLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_GrandJerseyWaterfrontUrbanRenewalAssociatesLLCMember_lbl" xml:lang="en-US">Grand Jersey Waterfront Urban Renewal Associates, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_GrandJerseyWaterfrontUrbanRenewalAssociatesLLCMember_lbl" xml:lang="en-US">Grand Jersey Waterfront Urban Renewal Associates L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_GrandJerseyWaterfrontUrbanRenewalAssociatesLLCMember_lbl" xml:lang="en-US">Grand Jersey Waterfront URA, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_HillsboroughTwoHundredSixHoldingsLLCMember" xlink:label="cli_HillsboroughTwoHundredSixHoldingsLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_HillsboroughTwoHundredSixHoldingsLLCMember" xlink:to="cli_HillsboroughTwoHundredSixHoldingsLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_HillsboroughTwoHundredSixHoldingsLLCMember_lbl" xml:lang="en-US">Hillsborough 206 Holdings, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_HillsboroughTwoHundredSixHoldingsLLCMember_lbl" xml:lang="en-US">Hillsborough Two Hundred Six Holdings L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_HillsboroughTwoHundredSixHoldingsLLCMember_lbl" xml:lang="en-US">Hillsborough 206 Holdings, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PlazaEightAndNineAssociatesLLCMember" xlink:label="cli_PlazaEightAndNineAssociatesLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PlazaEightAndNineAssociatesLLCMember" xlink:to="cli_PlazaEightAndNineAssociatesLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PlazaEightAndNineAssociatesLLCMember_lbl" xml:lang="en-US">Plaza 8 &amp; 9 Associates, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PlazaEightAndNineAssociatesLLCMember_lbl" xml:lang="en-US">Plaza Eight And Nine Associates L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PlazaEightAndNineAssociatesLLCMember_lbl" xml:lang="en-US">Plaza VIII &amp; IX Associates, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PruRosePortImperialSouthFifteenLLCMember" xlink:label="cli_PruRosePortImperialSouthFifteenLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PruRosePortImperialSouthFifteenLLCMember" xlink:to="cli_PruRosePortImperialSouthFifteenLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PruRosePortImperialSouthFifteenLLCMember_lbl" xml:lang="en-US">PruRose Port Imperial South 15, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PruRosePortImperialSouthFifteenLLCMember_lbl" xml:lang="en-US">Pru Rose Port Imperial South Fifteen L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PruRosePortImperialSouthFifteenLLCMember_lbl" xml:lang="en-US">PruRose Port Imperial South 15, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PruRosePortImperialSouthThirteenLLCMember" xlink:label="cli_PruRosePortImperialSouthThirteenLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PruRosePortImperialSouthThirteenLLCMember" xlink:to="cli_PruRosePortImperialSouthThirteenLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PruRosePortImperialSouthThirteenLLCMember_lbl" xml:lang="en-US">PruRose Port Imperial South 13, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PruRosePortImperialSouthThirteenLLCMember_lbl" xml:lang="en-US">Pru Rose Port Imperial South Thirteen L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PruRosePortImperialSouthThirteenLLCMember_lbl" xml:lang="en-US">PruRose Port Imperial South 13, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CrystalHouseApartmentsInvestorsLLCMember" xlink:label="cli_CrystalHouseApartmentsInvestorsLLCMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CrystalHouseApartmentsInvestorsLLCMember" xlink:to="cli_CrystalHouseApartmentsInvestorsLLCMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CrystalHouseApartmentsInvestorsLLCMember_lbl" xml:lang="en-US">Crystal House Apartments Investors LLC [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CrystalHouseApartmentsInvestorsLLCMember_lbl" xml:lang="en-US">Crystal House Apartments Investors L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_CrystalHouseApartmentsInvestorsLLCMember_lbl" xml:lang="en-US">Crystal House Apartments Investors LLC [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RiverwalkCUrbanRenewalL.l.c.Member" xlink:label="cli_RiverwalkCUrbanRenewalL.l.c.Member" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RiverwalkCUrbanRenewalL.l.c.Member" xlink:to="cli_RiverwalkCUrbanRenewalL.l.c.Member_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RiverwalkCUrbanRenewalL.l.c.Member_lbl" xml:lang="en-US">Riverwalk C Urban Renewal, L.L.C. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RiverwalkCUrbanRenewalL.l.c.Member_lbl" xml:lang="en-US">Riverwalk C Urban Renewal L.l.c. [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RiverwalkCUrbanRenewalL.l.c.Member_lbl" xml:lang="en-US">Riverwalk C Urban Renewal, L.L.C. [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OtherJointVenturesMember" xlink:label="cli_OtherJointVenturesMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OtherJointVenturesMember" xlink:to="cli_OtherJointVenturesMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OtherJointVenturesMember_lbl" xml:lang="en-US">Other Joint Ventures [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OtherJointVenturesMember_lbl" xml:lang="en-US">Other Joint Ventures [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OtherJointVenturesMember_lbl" xml:lang="en-US">Other [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LiborInterestRate" xlink:label="cli_LiborInterestRate" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LiborInterestRate" xlink:to="cli_LiborInterestRate_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LiborInterestRate_lbl" xml:lang="en-US">Libor Interest Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LiborInterestRate_lbl" xml:lang="en-US">Libor Interest Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_LiborInterestRate_lbl" xml:lang="en-US">LIBOR</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_LiborInterestRate_lbl" xml:lang="en-US">Property Debt, Interest Rate, LIBOR</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ResidualOwnershipInterest" xlink:label="cli_ResidualOwnershipInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ResidualOwnershipInterest" xlink:to="cli_ResidualOwnershipInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ResidualOwnershipInterest_lbl" xml:lang="en-US">Residual Ownership Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ResidualOwnershipInterest_lbl" xml:lang="en-US">Residual Ownership Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ResidualOwnershipInterest_lbl" xml:lang="en-US">Residual ownership interest</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_IndirectOwnershipPercentage" xlink:label="cli_IndirectOwnershipPercentage" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_IndirectOwnershipPercentage" xlink:to="cli_IndirectOwnershipPercentage_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_IndirectOwnershipPercentage_lbl" xml:lang="en-US">Indirect Ownership Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_IndirectOwnershipPercentage_lbl" xml:lang="en-US">Indirect Ownership Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_IndirectOwnershipPercentage_lbl" xml:lang="en-US">Indirect ownership interest</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SubordinateInterest" xlink:label="cli_SubordinateInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SubordinateInterest" xlink:to="cli_SubordinateInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SubordinateInterest_lbl" xml:lang="en-US">Subordinate Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SubordinateInterest_lbl" xml:lang="en-US">Subordinate Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SubordinateInterest_lbl" xml:lang="en-US">Subordinate interest</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireBusinessesGross" xlink:to="us-gaap_PaymentsToAcquireBusinessesGross_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross_lbl" xml:lang="en-US">Business Acquisition, Cost of Acquired Entity, Cash Paid</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross_lbl" xml:lang="en-US">Cash consideration</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtInstrumentExtensionFeePercentage" xlink:label="cli_DebtInstrumentExtensionFeePercentage" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtInstrumentExtensionFeePercentage" xlink:to="cli_DebtInstrumentExtensionFeePercentage_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtInstrumentExtensionFeePercentage_lbl" xml:lang="en-US">Debt Instrument Extension Fee Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtInstrumentExtensionFeePercentage_lbl" xml:lang="en-US">Debt Instrument Extension Fee Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DebtInstrumentExtensionFeePercentage_lbl" xml:lang="en-US">Extension fee</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PercentageOfInterestInDevelopableLand" xlink:label="cli_PercentageOfInterestInDevelopableLand" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PercentageOfInterestInDevelopableLand" xlink:to="cli_PercentageOfInterestInDevelopableLand_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PercentageOfInterestInDevelopableLand_lbl" xml:lang="en-US">Percentage Of Interest In Developable Land</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PercentageOfInterestInDevelopableLand_lbl" xml:lang="en-US">Percentage Of Interest In Developable Land</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PercentageOfInterestInDevelopableLand_lbl" xml:lang="en-US">Percentage of interest in developable land</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfUnitsAvailableForDevelopment" xlink:label="cli_NumberOfUnitsAvailableForDevelopment" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfUnitsAvailableForDevelopment" xlink:to="cli_NumberOfUnitsAvailableForDevelopment_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfUnitsAvailableForDevelopment_lbl" xml:lang="en-US">Number Of Units Available For Development</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfUnitsAvailableForDevelopment_lbl" xml:lang="en-US">Number Of Units Available For Development</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfUnitsAvailableForDevelopment_lbl" xml:lang="en-US">Number of units available for development</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfApprovedUnitsAvailableForDevelopment" xlink:label="cli_NumberOfApprovedUnitsAvailableForDevelopment" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfApprovedUnitsAvailableForDevelopment" xlink:to="cli_NumberOfApprovedUnitsAvailableForDevelopment_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfApprovedUnitsAvailableForDevelopment_lbl" xml:lang="en-US">Number Of Approved Units Available For Development</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfApprovedUnitsAvailableForDevelopment_lbl" xml:lang="en-US">Number Of Approved Units Available For Development</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfApprovedUnitsAvailableForDevelopment_lbl" xml:lang="en-US">Number of approved units available for development</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:to="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl" xml:lang="en-US">Debt Instrument, Interest Rate, Effective Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl" xml:lang="en-US">Effective rate</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgageLoansOnRealEstateFaceAmountOfMortgages" xlink:label="us-gaap_MortgageLoansOnRealEstateFaceAmountOfMortgages" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MortgageLoansOnRealEstateFaceAmountOfMortgages" xlink:to="us-gaap_MortgageLoansOnRealEstateFaceAmountOfMortgages_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageLoansOnRealEstateFaceAmountOfMortgages_lbl" xml:lang="en-US">Mortgage Loans on Real Estate, Face Amount of Mortgages</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MortgageLoansOnRealEstateFaceAmountOfMortgages_lbl" xml:lang="en-US">Mortgage loan face amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_MortgageLoansOnRealEstateFaceAmountOfMortgages_lbl" xml:lang="en-US">Face Amount of Mortgages or Maximum Available Credit</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfPropertiesUsedToCollateralizeMortgage" xlink:label="cli_NumberOfPropertiesUsedToCollateralizeMortgage" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfPropertiesUsedToCollateralizeMortgage" xlink:to="cli_NumberOfPropertiesUsedToCollateralizeMortgage_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfPropertiesUsedToCollateralizeMortgage_lbl" xml:lang="en-US">Number Of Properties Used To Collateralize Mortgage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfPropertiesUsedToCollateralizeMortgage_lbl" xml:lang="en-US">Number Of Properties Used To Collateralize Mortgage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfPropertiesUsedToCollateralizeMortgage_lbl" xml:lang="en-US">Number of properties used to collateralized mortgage</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EquityMethodInvestmentAmortizationOfBasisDifference" xlink:label="cli_EquityMethodInvestmentAmortizationOfBasisDifference" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EquityMethodInvestmentAmortizationOfBasisDifference" xlink:to="cli_EquityMethodInvestmentAmortizationOfBasisDifference_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EquityMethodInvestmentAmortizationOfBasisDifference_lbl" xml:lang="en-US">Equity Method Investment, Amortization Of Basis Difference</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EquityMethodInvestmentAmortizationOfBasisDifference_lbl" xml:lang="en-US">Equity Method Investment, Amortization Of Basis Difference</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_EquityMethodInvestmentAmortizationOfBasisDifference_lbl" xml:lang="en-US">Amortization of basis difference</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EquityMethodInvestmentSummarizedFinancialInformationRentalPropertyNet" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationRentalPropertyNet" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EquityMethodInvestmentSummarizedFinancialInformationRentalPropertyNet" xlink:to="cli_EquityMethodInvestmentSummarizedFinancialInformationRentalPropertyNet_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationRentalPropertyNet_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Rental Property, Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationRentalPropertyNet_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Rental Property, Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationRentalPropertyNet_lbl" xml:lang="en-US">Rental property, net</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EquityMethodInvestmentSummarizedFinancialInformationOtherAssets" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationOtherAssets" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EquityMethodInvestmentSummarizedFinancialInformationOtherAssets" xlink:to="cli_EquityMethodInvestmentSummarizedFinancialInformationOtherAssets_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationOtherAssets_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Other Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationOtherAssets_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Other Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationOtherAssets_lbl" xml:lang="en-US">Other assets</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital" xlink:to="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Equity or Capital</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital_lbl" xml:lang="en-US">Partners'/members' capital</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity" xlink:to="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Liabilities and Equity</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity_lbl" xml:lang="en-US">Total liabilities and partners'/members' capital</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityMethodInvestmentSummarizedFinancialInformationRevenue" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationRevenue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationRevenue" xlink:to="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationRevenue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationRevenue_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Net Sales or Gross Revenue</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationRevenue_lbl" xml:lang="en-US">Total revenues</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EquityMethodInvestmentSummarizedFinancialInformationOperatingAndOther" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationOperatingAndOther" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationOperatingAndOther_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Operating and Other</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationOperatingAndOther_lbl" xml:lang="en-US">Operating and other expenses</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EquityMethodInvestmentSummarizedFinancialInformationDepreciationAndAmortization" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationDepreciationAndAmortization" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EquityMethodInvestmentSummarizedFinancialInformationDepreciationAndAmortization" xlink:to="cli_EquityMethodInvestmentSummarizedFinancialInformationDepreciationAndAmortization_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationDepreciationAndAmortization_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Depreciation and Amortization</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationDepreciationAndAmortization_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Depreciation and Amortization</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationDepreciationAndAmortization_lbl" xml:lang="en-US">Depreciation and amortization</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EquityMethodInvestmentSummarizedFinancialInformationInterestExpense" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationInterestExpense" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EquityMethodInvestmentSummarizedFinancialInformationInterestExpense" xlink:to="cli_EquityMethodInvestmentSummarizedFinancialInformationInterestExpense_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationInterestExpense_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Interest Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationInterestExpense_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Interest Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_EquityMethodInvestmentSummarizedFinancialInformationInterestExpense_lbl" xml:lang="en-US">Interest expense</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss" xlink:to="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss_lbl" xml:lang="en-US">Equity Method Investment, Summarized Financial Information, Net Income (Loss)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss_lbl" xml:lang="en-US">Net income (loss)</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" xlink:label="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_lbl" xml:lang="en-US">Derivative Instruments, Gain (Loss) [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems" xlink:label="us-gaap_DerivativeInstrumentsGainLossLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentsGainLossLineItems" xlink:to="us-gaap_DerivativeInstrumentsGainLossLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeInstrumentsGainLossLineItems_lbl" xml:lang="en-US">Derivative Instruments, Gain (Loss) [Line Items]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeLiabilityNotionalAmount" xlink:label="us-gaap_DerivativeLiabilityNotionalAmount" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeLiabilityNotionalAmount" xlink:to="us-gaap_DerivativeLiabilityNotionalAmount_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeLiabilityNotionalAmount_lbl" xml:lang="en-US">Derivative Liability, Notional Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativeLiabilityNotionalAmount_lbl" xml:lang="en-US">Derivative notional amount</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeNetHedgeIneffectivenessGainLoss" xlink:label="us-gaap_DerivativeNetHedgeIneffectivenessGainLoss" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeNetHedgeIneffectivenessGainLoss" xlink:to="us-gaap_DerivativeNetHedgeIneffectivenessGainLoss_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeNetHedgeIneffectivenessGainLoss_lbl" xml:lang="en-US">Derivative, Net Hedge Ineffectiveness Gain (Loss)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativeNetHedgeIneffectivenessGainLoss_lbl" xml:lang="en-US">Ineffective gain (loss) in interest expense</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths" xlink:label="us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths" xlink:to="us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths_lbl" xml:lang="en-US">Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths_lbl" xml:lang="en-US">Estimated additional amount to be reclassified to interest expense</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeGainLossOnDerivativeNet" xlink:label="us-gaap_DerivativeGainLossOnDerivativeNet" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeGainLossOnDerivativeNet" xlink:to="us-gaap_DerivativeGainLossOnDerivativeNet_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeGainLossOnDerivativeNet_lbl" xml:lang="en-US">Derivative, Gain (Loss) on Derivative, Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativeGainLossOnDerivativeNet_lbl" xml:lang="en-US">Amount of increase in the fair value of derivatives</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability" xlink:label="us-gaap_DerivativeFairValueOfDerivativeLiability" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeFairValueOfDerivativeLiability" xlink:to="us-gaap_DerivativeFairValueOfDerivativeLiability_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeFairValueOfDerivativeLiability_lbl" xml:lang="en-US">Derivative Liability, Fair Value, Gross Liability</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativeFairValueOfDerivativeLiability_lbl" xml:lang="en-US">Net liability</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredCostsLeasingGross" xlink:label="us-gaap_DeferredCostsLeasingGross" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredCostsLeasingGross" xlink:to="us-gaap_DeferredCostsLeasingGross_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredCostsLeasingGross_lbl" xml:lang="en-US">Deferred Costs, Leasing, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredCostsLeasingGross_lbl" xml:lang="en-US">Deferred leasing costs</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredFinanceCostsGross" xlink:label="us-gaap_DeferredFinanceCostsGross" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredFinanceCostsGross" xlink:to="us-gaap_DeferredFinanceCostsGross_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredFinanceCostsGross_lbl" xml:lang="en-US">Deferred Finance Costs, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredFinanceCostsGross_lbl" xml:lang="en-US">Deferred financing costs - unsecured revolving credit facility</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DeferredCostsGross" xlink:label="cli_DeferredCostsGross" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DeferredCostsGross" xlink:to="cli_DeferredCostsGross_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DeferredCostsGross_lbl" xml:lang="en-US">Deferred Costs, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DeferredCostsGross_lbl" xml:lang="en-US">Deferred Costs, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_DeferredCostsGross_lbl" xml:lang="en-US">Deferred charges, gross</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AccumulatedAmortizationLeasingAndFinancingCosts" xlink:label="cli_AccumulatedAmortizationLeasingAndFinancingCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AccumulatedAmortizationLeasingAndFinancingCosts" xlink:to="cli_AccumulatedAmortizationLeasingAndFinancingCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AccumulatedAmortizationLeasingAndFinancingCosts_lbl" xml:lang="en-US">Accumulated Amortization Leasing And Financing Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AccumulatedAmortizationLeasingAndFinancingCosts_lbl" xml:lang="en-US">Accumulated Amortization Leasing And Financing Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_AccumulatedAmortizationLeasingAndFinancingCosts_lbl" xml:lang="en-US">Accumulated amortization</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredCosts" xlink:label="us-gaap_DeferredCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredCosts" xlink:to="us-gaap_DeferredCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredCosts_lbl" xml:lang="en-US">Deferred charges, net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DeferredCosts_lbl" xml:lang="en-US">Deferred charges, net</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LoansAndLeasesReceivableNetReportedAmount" xlink:label="us-gaap_LoansAndLeasesReceivableNetReportedAmount" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansAndLeasesReceivableNetReportedAmount" xlink:to="us-gaap_LoansAndLeasesReceivableNetReportedAmount_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LoansAndLeasesReceivableNetReportedAmount_lbl" xml:lang="en-US">Loans and Leases Receivable, Net Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LoansAndLeasesReceivableNetReportedAmount_lbl" xml:lang="en-US">Notes receivable</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetAcquiredInPlaceLeases" xlink:label="us-gaap_FiniteLivedIntangibleAssetAcquiredInPlaceLeases" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetAcquiredInPlaceLeases" xlink:to="us-gaap_FiniteLivedIntangibleAssetAcquiredInPlaceLeases_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetAcquiredInPlaceLeases_lbl" xml:lang="en-US">Finite-Lived Intangible Asset, Acquired-in-Place Leases</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetAcquiredInPlaceLeases_lbl" xml:lang="en-US">In-place lease values, related intangibles and other assets, net</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Goodwill" xlink:to="us-gaap_Goodwill_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Goodwill_lbl" xml:lang="en-US">Business Acquisition, Purchase Price Allocation, Goodwill Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_Goodwill_lbl" xml:lang="en-US">Goodwill</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssets" xlink:label="us-gaap_PrepaidExpenseAndOtherAssets" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseAndOtherAssets" xlink:to="us-gaap_PrepaidExpenseAndOtherAssets_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PrepaidExpenseAndOtherAssets_lbl" xml:lang="en-US">Prepaid expenses and other assets, net</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:to="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_lbl" xml:lang="en-US">Schedule of Finite-Lived Intangible Assets [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl" xml:lang="en-US">Finite-Lived Intangible Assets [Line Items]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_lbl" xml:lang="en-US">Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_lbl" xml:lang="en-US">2018</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_lbl" xml:lang="en-US">Finite-Lived Intangible Assets, Amortization Expense, Year Two</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_lbl" xml:lang="en-US">2019</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_lbl" xml:lang="en-US">Finite-Lived Intangible Assets, Amortization Expense, Year Three</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_lbl" xml:lang="en-US">2020</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_lbl" xml:lang="en-US">Finite-Lived Intangible Assets, Amortization Expense, Year Four</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_lbl" xml:lang="en-US">2021</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_lbl" xml:lang="en-US">Finite-Lived Intangible Assets, Amortization Expense, Year Five</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_lbl" xml:lang="en-US">2022</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="us-gaap_AmortizationOfIntangibleAssets" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfIntangibleAssets" xlink:to="us-gaap_AmortizationOfIntangibleAssets_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AmortizationOfIntangibleAssets_lbl" xml:lang="en-US">Amortization of Intangible Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AmortizationOfIntangibleAssets_lbl" xml:lang="en-US">Amortization expense</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable" xlink:label="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable" xlink:to="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_lbl" xml:lang="en-US">Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeAssets" xlink:label="us-gaap_DerivativeAssets" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeAssets" xlink:to="us-gaap_DerivativeAssets_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeAssets_lbl" xml:lang="en-US">Derivative Asset</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativeAssets_lbl" xml:lang="en-US">Asset Derivatives</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet" xlink:label="us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet" xlink:to="us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet_lbl" xml:lang="en-US">Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet_lbl" xml:lang="en-US">Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion)</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet" xlink:label="us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet" xlink:to="us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_lbl" xml:lang="en-US">Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_lbl" xml:lang="en-US">Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet" xlink:label="us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet" xlink:to="us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet_lbl" xml:lang="en-US">Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet_lbl" xml:lang="en-US">Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion, Reclassification for Forecasted Transactions No Longer Probable of Occurring and Amount Excluded from Effectiveness Testing)</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SecurityDeposit" xlink:label="us-gaap_SecurityDeposit" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SecurityDeposit" xlink:to="us-gaap_SecurityDeposit_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SecurityDeposit_lbl" xml:lang="en-US">Security Deposit</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SecurityDeposit_lbl" xml:lang="en-US">Security deposits</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EscrowDeposit" xlink:label="us-gaap_EscrowDeposit" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EscrowDeposit" xlink:to="us-gaap_EscrowDeposit_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EscrowDeposit_lbl" xml:lang="en-US">Escrow Deposit</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EscrowDeposit_lbl" xml:lang="en-US">Escrow and other reserve funds</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscount" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentUnamortizedDiscount" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscount_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount_lbl" xml:lang="en-US">Debt Instrument, Unamortized Discount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount_lbl" xml:lang="en-US">Adjustment for unamortized debt discount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount_lbl" xml:lang="en-US">Adjustment for unamortized debt discount/premium, net December 31, 2017</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount_lbl" xml:lang="en-US">Adjustment for unamortized debt discount</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_UnamortizedDeferredFinancingCosts" xlink:label="cli_UnamortizedDeferredFinancingCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_UnamortizedDeferredFinancingCosts" xlink:to="cli_UnamortizedDeferredFinancingCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_UnamortizedDeferredFinancingCosts_lbl" xml:lang="en-US">Unamortized Deferred Financing Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_UnamortizedDeferredFinancingCosts_lbl" xml:lang="en-US">Unamortized Deferred Financing Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_UnamortizedDeferredFinancingCosts_lbl" xml:lang="en-US">Unamortized deferred financing costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_UnamortizedDeferredFinancingCosts_lbl" xml:lang="en-US">Unamortized deferred financing costs</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityTable" xlink:label="us-gaap_LineOfCreditFacilityTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityTable" xlink:to="us-gaap_LineOfCreditFacilityTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityTable_lbl" xml:lang="en-US">Line of Credit Facility [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityLineItems" xlink:label="us-gaap_LineOfCreditFacilityLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityLineItems" xlink:to="us-gaap_LineOfCreditFacilityLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityLineItems_lbl" xml:lang="en-US">Line of Credit Facility [Line Items]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnsecuredLongTermDebt" xlink:label="us-gaap_UnsecuredLongTermDebt" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnsecuredLongTermDebt" xlink:to="us-gaap_UnsecuredLongTermDebt_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnsecuredLongTermDebt_lbl" xml:lang="en-US">Unsecured Long-term Debt, Noncurrent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_UnsecuredLongTermDebt_lbl" xml:lang="en-US">Unsecured term loan, net</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeAverageVariableInterestRate" xlink:label="us-gaap_DerivativeAverageVariableInterestRate" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeAverageVariableInterestRate" xlink:to="us-gaap_DerivativeAverageVariableInterestRate_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeAverageVariableInterestRate_lbl" xml:lang="en-US">Derivative, Average Variable Interest Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativeAverageVariableInterestRate_lbl" xml:lang="en-US">Interest rate swap</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LineOfCreditFacilityLendingInstitutionsNumber" xlink:label="cli_LineOfCreditFacilityLendingInstitutionsNumber" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LineOfCreditFacilityLendingInstitutionsNumber" xlink:to="cli_LineOfCreditFacilityLendingInstitutionsNumber_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LineOfCreditFacilityLendingInstitutionsNumber_lbl" xml:lang="en-US">Line of Credit Facility, Lending Institutions Number</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LineOfCreditFacilityLendingInstitutionsNumber_lbl" xml:lang="en-US">Line of Credit Facility, Lending Institutions Number</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_LineOfCreditFacilityLendingInstitutionsNumber_lbl" xml:lang="en-US">Number of lending institutions</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LineOfCreditFacilityExtensionPeriod" xlink:label="cli_LineOfCreditFacilityExtensionPeriod" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LineOfCreditFacilityExtensionPeriod" xlink:to="cli_LineOfCreditFacilityExtensionPeriod_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LineOfCreditFacilityExtensionPeriod_lbl" xml:lang="en-US">Line Of Credit Facility Extension Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LineOfCreditFacilityExtensionPeriod_lbl" xml:lang="en-US">Line Of Credit Facility Extension Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_LineOfCreditFacilityExtensionPeriod_lbl" xml:lang="en-US">Credit facility, extension period</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtInstrumentCovenantComplianceLeverageRatio" xlink:label="cli_DebtInstrumentCovenantComplianceLeverageRatio" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtInstrumentCovenantComplianceLeverageRatio" xlink:to="cli_DebtInstrumentCovenantComplianceLeverageRatio_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtInstrumentCovenantComplianceLeverageRatio_lbl" xml:lang="en-US">Debt Instrument Covenant Compliance, Leverage Ratio</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtInstrumentCovenantComplianceLeverageRatio_lbl" xml:lang="en-US">Debt Instrument Covenant Compliance, Leverage Ratio</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DebtInstrumentCovenantComplianceLeverageRatio_lbl" xml:lang="en-US">Leverage ratio</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityCovenantTerms" xlink:label="us-gaap_LineOfCreditFacilityCovenantTerms" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityCovenantTerms" xlink:to="us-gaap_LineOfCreditFacilityCovenantTerms_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityCovenantTerms_lbl" xml:lang="en-US">Line of Credit Facility, Covenant Terms</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LineOfCreditFacilityCovenantTerms_lbl" xml:lang="en-US">Terms of the unsecured facility</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityDividendRestrictions" xlink:label="us-gaap_LineOfCreditFacilityDividendRestrictions" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityDividendRestrictions" xlink:to="us-gaap_LineOfCreditFacilityDividendRestrictions_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityDividendRestrictions_lbl" xml:lang="en-US">Line of Credit Facility, Dividend Restrictions</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LineOfCreditFacilityDividendRestrictions_lbl" xml:lang="en-US">Terms of dividend restriction</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentTerm" xlink:label="us-gaap_DebtInstrumentTerm" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentTerm" xlink:to="us-gaap_DebtInstrumentTerm_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentTerm_lbl" xml:lang="en-US">Debt Instrument, Term</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentTerm_lbl" xml:lang="en-US">Loan period</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtInstrumentInitialTermCommitmentPercentageBorrowed" xlink:label="cli_DebtInstrumentInitialTermCommitmentPercentageBorrowed" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtInstrumentInitialTermCommitmentPercentageBorrowed" xlink:to="cli_DebtInstrumentInitialTermCommitmentPercentageBorrowed_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtInstrumentInitialTermCommitmentPercentageBorrowed_lbl" xml:lang="en-US">Debt Instrument, Initial Term Commitment Percentage Borrowed</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtInstrumentInitialTermCommitmentPercentageBorrowed_lbl" xml:lang="en-US">Debt Instrument, Initial Term Commitment Percentage Borrowed</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DebtInstrumentInitialTermCommitmentPercentageBorrowed_lbl" xml:lang="en-US">Minimum percentage of initial borrowing</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtInstrumentTermCommitmentFeePerAnnum" xlink:label="cli_DebtInstrumentTermCommitmentFeePerAnnum" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtInstrumentTermCommitmentFeePerAnnum" xlink:to="cli_DebtInstrumentTermCommitmentFeePerAnnum_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtInstrumentTermCommitmentFeePerAnnum_lbl" xml:lang="en-US">Debt Instrument, Term Commitment Fee Per Annum</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtInstrumentTermCommitmentFeePerAnnum_lbl" xml:lang="en-US">Debt Instrument, Term Commitment Fee Per Annum</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DebtInstrumentTermCommitmentFeePerAnnum_lbl" xml:lang="en-US">Term commitment fee percent</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LineOfCreditFacilityMaximumBorrowingCapacityThatMayBeElectedAfterEffectiveLoanDate" xlink:label="cli_LineOfCreditFacilityMaximumBorrowingCapacityThatMayBeElectedAfterEffectiveLoanDate" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LineOfCreditFacilityMaximumBorrowingCapacityThatMayBeElectedAfterEffectiveLoanDate" xlink:to="cli_LineOfCreditFacilityMaximumBorrowingCapacityThatMayBeElectedAfterEffectiveLoanDate_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LineOfCreditFacilityMaximumBorrowingCapacityThatMayBeElectedAfterEffectiveLoanDate_lbl" xml:lang="en-US">Line of Credit Facility, Maximum Borrowing Capacity That May Be Elected After Effective Loan Date</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LineOfCreditFacilityMaximumBorrowingCapacityThatMayBeElectedAfterEffectiveLoanDate_lbl" xml:lang="en-US">Line of Credit Facility, Maximum Borrowing Capacity That May Be Elected After Effective Loan Date</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_LineOfCreditFacilityMaximumBorrowingCapacityThatMayBeElectedAfterEffectiveLoanDate_lbl" xml:lang="en-US">Maximum loan increase that may be requested</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:label="us-gaap_LineOfCreditFacilityCommitmentFeePercentage" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:to="us-gaap_LineOfCreditFacilityCommitmentFeePercentage_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityCommitmentFeePercentage_lbl" xml:lang="en-US">Line of Credit Facility, Basis Points of Facility Fees</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityCommitmentFeePercentage_lbl" xml:lang="en-US">Facility fee basis points</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LineOfCreditFacilityCommitmentFeePercentage_lbl" xml:lang="en-US">Facility Fee Basis Points</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentCreditRating" xlink:label="us-gaap_DebtInstrumentCreditRating" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentCreditRating" xlink:to="us-gaap_DebtInstrumentCreditRating_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentCreditRating_lbl" xml:lang="en-US">Debt Instrument, Credit Rating</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentCreditRating_lbl" xml:lang="en-US">Unsecured Debt Ratings</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="us-gaap_DebtInstrumentAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xml:lang="en-US">Debt Instrument [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="us-gaap_DebtInstrumentNameDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentNameDomain" xlink:to="us-gaap_DebtInstrumentNameDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xml:lang="en-US">Debt Instrument Name [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xml:lang="en-US">Debt Instrument, Name [Domain]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RevolvingCreditFacilityAndOtherVariableRateMortgageDebtMember" xlink:label="cli_RevolvingCreditFacilityAndOtherVariableRateMortgageDebtMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RevolvingCreditFacilityAndOtherVariableRateMortgageDebtMember" xlink:to="cli_RevolvingCreditFacilityAndOtherVariableRateMortgageDebtMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RevolvingCreditFacilityAndOtherVariableRateMortgageDebtMember_lbl" xml:lang="en-US">Revolving Credit Facility and Other Variable Rate Mortgage Debt [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RevolvingCreditFacilityAndOtherVariableRateMortgageDebtMember_lbl" xml:lang="en-US">Revolving Credit Facility And Other Variable Rate Mortgage Debt [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RevolvingCreditFacilityAndOtherVariableRateMortgageDebtMember_lbl" xml:lang="en-US">Revolving Credit Facility Borrowing And Other Variable Rate Mortgage Debt [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FixedRateDebtAndOtherObligationsMember" xlink:label="cli_FixedRateDebtAndOtherObligationsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FixedRateDebtAndOtherObligationsMember" xlink:to="cli_FixedRateDebtAndOtherObligationsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FixedRateDebtAndOtherObligationsMember_lbl" xml:lang="en-US">Fixed Rate Debt and Other Obligations [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FixedRateDebtAndOtherObligationsMember_lbl" xml:lang="en-US">Fixed Rate Debt And Other Obligations [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FixedRateDebtAndOtherObligationsMember_lbl" xml:lang="en-US">Fixed Rate Debt And Other Obligations [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfPropertiesWithEncumberedCompanyMortgages" xlink:label="cli_NumberOfPropertiesWithEncumberedCompanyMortgages" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfPropertiesWithEncumberedCompanyMortgages" xlink:to="cli_NumberOfPropertiesWithEncumberedCompanyMortgages_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfPropertiesWithEncumberedCompanyMortgages_lbl" xml:lang="en-US">Number Of Properties With Encumbered Company Mortgages</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfPropertiesWithEncumberedCompanyMortgages_lbl" xml:lang="en-US">Number Of Properties With Encumbered Company Mortgages</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfPropertiesWithEncumberedCompanyMortgages_lbl" xml:lang="en-US">Number of properties with encumbered company mortgages</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfProjectsWithEncumberedCompanyMortgages" xlink:label="cli_NumberOfProjectsWithEncumberedCompanyMortgages" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfProjectsWithEncumberedCompanyMortgages" xlink:to="cli_NumberOfProjectsWithEncumberedCompanyMortgages_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfProjectsWithEncumberedCompanyMortgages_lbl" xml:lang="en-US">Number Of Projects With Encumbered Company Mortgages</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfProjectsWithEncumberedCompanyMortgages_lbl" xml:lang="en-US">Number Of Projects With Encumbered Company Mortgages</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfProjectsWithEncumberedCompanyMortgages_lbl" xml:lang="en-US">Number of projects with encumbered company mortgages</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MortgagePropertyCarryingValue" xlink:label="cli_MortgagePropertyCarryingValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MortgagePropertyCarryingValue" xlink:to="cli_MortgagePropertyCarryingValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MortgagePropertyCarryingValue_lbl" xml:lang="en-US">Carrying Value of the Mortgaged Property</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MortgagePropertyCarryingValue_lbl" xml:lang="en-US">Mortgage Property, Carrying Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MortgagePropertyCarryingValue_lbl" xml:lang="en-US">Carrying value of encumbered properties</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InterestPaid" xlink:label="us-gaap_InterestPaid" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPaid" xlink:to="us-gaap_InterestPaid_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestPaid_lbl" xml:lang="en-US">Interest Paid</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InterestPaid_lbl" xml:lang="en-US">Cash paid for interest</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InterestCostsCapitalized" xlink:label="us-gaap_InterestCostsCapitalized" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestCostsCapitalized" xlink:to="us-gaap_InterestCostsCapitalized_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestCostsCapitalized_lbl" xml:lang="en-US">Interest Costs, Capitalized During Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InterestCostsCapitalized_lbl" xml:lang="en-US">Interest capitalized</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LongTermDebtAdjustedTotalDebtBeforeDebtDiscountAndDeferredFinancingCosts" xlink:label="cli_LongTermDebtAdjustedTotalDebtBeforeDebtDiscountAndDeferredFinancingCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LongTermDebtAdjustedTotalDebtBeforeDebtDiscountAndDeferredFinancingCosts" xlink:to="cli_LongTermDebtAdjustedTotalDebtBeforeDebtDiscountAndDeferredFinancingCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LongTermDebtAdjustedTotalDebtBeforeDebtDiscountAndDeferredFinancingCosts_lbl" xml:lang="en-US">Long-term Debt, Adjusted Total Debt Before Debt Discount And Deferred Financing Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LongTermDebtAdjustedTotalDebtBeforeDebtDiscountAndDeferredFinancingCosts_lbl" xml:lang="en-US">Long-term Debt, Adjusted Total Debt Before Debt Discount And Deferred Financing Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_LongTermDebtAdjustedTotalDebtBeforeDebtDiscountAndDeferredFinancingCosts_lbl" xml:lang="en-US">Adjusted total indebtedness</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtWeightedAverageInterestRate" xlink:label="us-gaap_LongtermDebtWeightedAverageInterestRate" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongtermDebtWeightedAverageInterestRate" xlink:to="us-gaap_LongtermDebtWeightedAverageInterestRate_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongtermDebtWeightedAverageInterestRate_lbl" xml:lang="en-US">Long-term Debt, Weighted Average Interest Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongtermDebtWeightedAverageInterestRate_lbl" xml:lang="en-US">Total indebtedness, weighted average interest rate</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PortImperialFourFiveHotelMember" xlink:label="cli_PortImperialFourFiveHotelMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PortImperialFourFiveHotelMember" xlink:to="cli_PortImperialFourFiveHotelMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PortImperialFourFiveHotelMember_lbl" xml:lang="en-US">Port Imperial Four Five Hotel [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PortImperialFourFiveHotelMember_lbl" xml:lang="en-US">Port Imperial Four Five Hotel [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PortImperialFourFiveHotelMember_lbl" xml:lang="en-US">Port Imperial 4/5 Hotel [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CurtisCenterMember" xlink:label="cli_CurtisCenterMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CurtisCenterMember" xlink:to="cli_CurtisCenterMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CurtisCenterMember_lbl" xml:lang="en-US">Curtis Center [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CurtisCenterMember_lbl" xml:lang="en-US">Curtis Center [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_CurtisCenterMember_lbl" xml:lang="en-US">Curtis Center [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwentyThreeMainStreetMember" xlink:label="cli_TwentyThreeMainStreetMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwentyThreeMainStreetMember" xlink:to="cli_TwentyThreeMainStreetMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwentyThreeMainStreetMember_lbl" xml:lang="en-US">Twenty Three Main Street [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwentyThreeMainStreetMember_lbl" xml:lang="en-US">Twenty Three Main Street [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwentyThreeMainStreetMember_lbl" xml:lang="en-US">23 Main Street [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_HarborsidePlazaFiveMember" xlink:label="cli_HarborsidePlazaFiveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_HarborsidePlazaFiveMember" xlink:to="cli_HarborsidePlazaFiveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_HarborsidePlazaFiveMember_lbl" xml:lang="en-US">Harborside Plaza 5</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_HarborsidePlazaFiveMember_lbl" xml:lang="en-US">Harborside Plaza Five [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_HarborsidePlazaFiveMember_lbl" xml:lang="en-US">Harborside Plaza 5 [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneRiverCenterMember" xlink:label="cli_OneRiverCenterMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneRiverCenterMember" xlink:to="cli_OneRiverCenterMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneRiverCenterMember_lbl" xml:lang="en-US">One River Center</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneRiverCenterMember_lbl" xml:lang="en-US">One River Center [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneRiverCenterMember_lbl" xml:lang="en-US">One River Center [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SecuredDebtNameOfProperty" xlink:label="cli_SecuredDebtNameOfProperty" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SecuredDebtNameOfProperty" xlink:to="cli_SecuredDebtNameOfProperty_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SecuredDebtNameOfProperty_lbl" xml:lang="en-US">Secured Debt, Name of the Property</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SecuredDebtNameOfProperty_lbl" xml:lang="en-US">Secured Debt, Name of the Property</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SecuredDebtNameOfProperty_lbl" xml:lang="en-US">Property Name</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SecuredDebtLendingInstitution" xlink:label="cli_SecuredDebtLendingInstitution" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SecuredDebtLendingInstitution" xlink:to="cli_SecuredDebtLendingInstitution_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SecuredDebtLendingInstitution_lbl" xml:lang="en-US">Secured Debt, Lending Institution</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SecuredDebtLendingInstitution_lbl" xml:lang="en-US">Secured Debt, Lending Institution</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SecuredDebtLendingInstitution_lbl" xml:lang="en-US">Lender</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtLoansPayableAndOtherObligationsNet_lbl" xml:lang="en-US">Debt, Loans Payable, And Other Obligations, Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_DebtLoansPayableAndOtherObligationsNet_lbl" xml:lang="en-US">Total mortgages, loans payable and other obligations, net</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MortgagesLoansPayabesAndOtherObligationsTable" xlink:label="cli_MortgagesLoansPayabesAndOtherObligationsTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MortgagesLoansPayabesAndOtherObligationsTable" xlink:to="cli_MortgagesLoansPayabesAndOtherObligationsTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MortgagesLoansPayabesAndOtherObligationsTable_lbl" xml:lang="en-US">Mortgages, Loans Payabes And Other Obligations [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MortgagesLoansPayabesAndOtherObligationsTable_lbl" xml:lang="en-US">Mortgages, Loans Payabes And Other Obligations [Table]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MortgagesLoansPayabesAndOtherObligationsLineItems" xlink:label="cli_MortgagesLoansPayabesAndOtherObligationsLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MortgagesLoansPayabesAndOtherObligationsLineItems" xlink:to="cli_MortgagesLoansPayabesAndOtherObligationsLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MortgagesLoansPayabesAndOtherObligationsLineItems_lbl" xml:lang="en-US">Mortgages, Loans Payabes And Other Obligations [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MortgagesLoansPayabesAndOtherObligationsLineItems_lbl" xml:lang="en-US">Mortgages, Loans Payabes And Other Obligations [Line Items]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtDiscountPremiumFutureAmortizationYearOne" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearOne" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtDiscountPremiumFutureAmortizationYearOne" xlink:to="cli_DebtDiscountPremiumFutureAmortizationYearOne_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearOne_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Year One</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearOne_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Year One</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearOne_lbl" xml:lang="en-US">Scheduled Amortization, 2018</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtDiscountPremiumFutureAmortizationYearTwo" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearTwo" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtDiscountPremiumFutureAmortizationYearTwo" xlink:to="cli_DebtDiscountPremiumFutureAmortizationYearTwo_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearTwo_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Year Two</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearTwo_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Year Two</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearTwo_lbl" xml:lang="en-US">Scheduled Amortization, 2019</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtDiscountPremiumFutureAmortizationYearThree" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearThree" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtDiscountPremiumFutureAmortizationYearThree" xlink:to="cli_DebtDiscountPremiumFutureAmortizationYearThree_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearThree_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Year Three</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearThree_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Year Three</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearThree_lbl" xml:lang="en-US">Scheduled Amortization, 2020</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtDiscountPremiumFutureAmortizationYearFour" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearFour" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtDiscountPremiumFutureAmortizationYearFour" xlink:to="cli_DebtDiscountPremiumFutureAmortizationYearFour_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearFour_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Year Four</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearFour_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Year Four</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearFour_lbl" xml:lang="en-US">Scheduled Amortization, 2021</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtDiscountPremiumFutureAmortizationYearFive" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearFive" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtDiscountPremiumFutureAmortizationYearFive" xlink:to="cli_DebtDiscountPremiumFutureAmortizationYearFive_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearFive_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Year Five</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearFive_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Year Five</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DebtDiscountPremiumFutureAmortizationYearFive_lbl" xml:lang="en-US">Scheduled Amortization, 2022</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtDiscountPremiumFutureAmortizationThereafter" xlink:label="cli_DebtDiscountPremiumFutureAmortizationThereafter" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtDiscountPremiumFutureAmortizationThereafter" xlink:to="cli_DebtDiscountPremiumFutureAmortizationThereafter_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtDiscountPremiumFutureAmortizationThereafter_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Thereafter</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtDiscountPremiumFutureAmortizationThereafter_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Thereafter</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DebtDiscountPremiumFutureAmortizationThereafter_lbl" xml:lang="en-US">Scheduled Amortization, Thereafter</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtDiscountPremiumFutureAmortizationGross" xlink:label="cli_DebtDiscountPremiumFutureAmortizationGross" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtDiscountPremiumFutureAmortizationGross" xlink:to="cli_DebtDiscountPremiumFutureAmortizationGross_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtDiscountPremiumFutureAmortizationGross_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtDiscountPremiumFutureAmortizationGross_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_DebtDiscountPremiumFutureAmortizationGross_lbl" xml:lang="en-US">Scheduled Amortization, Sub-total</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtInstrumentPremiumFutureAmortizationUnamortizedMarkToMarket" xlink:label="cli_DebtInstrumentPremiumFutureAmortizationUnamortizedMarkToMarket" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtInstrumentPremiumFutureAmortizationUnamortizedMarkToMarket" xlink:to="cli_DebtInstrumentPremiumFutureAmortizationUnamortizedMarkToMarket_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtInstrumentPremiumFutureAmortizationUnamortizedMarkToMarket_lbl" xml:lang="en-US">Debt Instrument, Premium Future Amortization Unamortized Mark To Market</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtInstrumentPremiumFutureAmortizationUnamortizedMarkToMarket_lbl" xml:lang="en-US">Debt Instrument, Premium Future Amortization Unamortized Mark To Market</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_DebtInstrumentPremiumFutureAmortizationUnamortizedMarkToMarket_lbl" xml:lang="en-US">Scheduled Amortization, Unamortized mark to market</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtInstrumentUnamortizedDiscountCosts" xlink:label="cli_DebtInstrumentUnamortizedDiscountCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtInstrumentUnamortizedDiscountCosts" xlink:to="cli_DebtInstrumentUnamortizedDiscountCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtInstrumentUnamortizedDiscountCosts_lbl" xml:lang="en-US">Debt Instrument, Unamortized Discount Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtInstrumentUnamortizedDiscountCosts_lbl" xml:lang="en-US">Debt Instrument, Unamortized Discount Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:label="cli_DebtInstrumentUnamortizedDiscountCosts_lbl" xml:lang="en-US">Unamortized deferred financing costs</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtDiscountPremiumFutureAmortizationNet" xlink:label="cli_DebtDiscountPremiumFutureAmortizationNet" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtDiscountPremiumFutureAmortizationNet" xlink:to="cli_DebtDiscountPremiumFutureAmortizationNet_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtDiscountPremiumFutureAmortizationNet_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtDiscountPremiumFutureAmortizationNet_lbl" xml:lang="en-US">Debt Discount Premium Future Amortization Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_DebtDiscountPremiumFutureAmortizationNet_lbl" xml:lang="en-US">Scheduled Amortization, Total</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl" xml:lang="en-US">Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl" xml:lang="en-US">Principal Maturities, 2018</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl" xml:lang="en-US">Long-term Debt, Maturities, Repayments of Principal in Year Two</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl" xml:lang="en-US">Principal Maturities, 2019</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl" xml:lang="en-US">Long-term Debt, Maturities, Repayments of Principal in Year Three</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl" xml:lang="en-US">Principal Maturities, 2020</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl" xml:lang="en-US">Long-term Debt, Maturities, Repayments of Principal in Year Four</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl" xml:lang="en-US">Principal Maturities, 2021</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl" xml:lang="en-US">Long-term Debt, Maturities, Repayments of Principal in Year Five</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl" xml:lang="en-US">Principal Maturities, 2022</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_lbl" xml:lang="en-US">Long-term Debt, Maturities, Repayments of Principal after Year Five</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_lbl" xml:lang="en-US">Principal Maturities, Thereafter</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LongTermDebtMaturitiesRepaymentsOfPrincipalGross" xlink:label="cli_LongTermDebtMaturitiesRepaymentsOfPrincipalGross" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LongTermDebtMaturitiesRepaymentsOfPrincipalGross" xlink:to="cli_LongTermDebtMaturitiesRepaymentsOfPrincipalGross_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LongTermDebtMaturitiesRepaymentsOfPrincipalGross_lbl" xml:lang="en-US">Long Term Debt Maturities Repayments Of Principal Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LongTermDebtMaturitiesRepaymentsOfPrincipalGross_lbl" xml:lang="en-US">Long Term Debt Maturities Repayments Of Principal Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_LongTermDebtMaturitiesRepaymentsOfPrincipalGross_lbl" xml:lang="en-US">Principal Maturities, Sub-total</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LongTermDebtMaturitiesRepaymentsOfPrincipal" xlink:label="cli_LongTermDebtMaturitiesRepaymentsOfPrincipal" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LongTermDebtMaturitiesRepaymentsOfPrincipal" xlink:to="cli_LongTermDebtMaturitiesRepaymentsOfPrincipal_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LongTermDebtMaturitiesRepaymentsOfPrincipal_lbl" xml:lang="en-US">Long Term Debt Maturities, Repayments Of Principal</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LongTermDebtMaturitiesRepaymentsOfPrincipal_lbl" xml:lang="en-US">Long Term Debt Maturities, Repayments Of Principal</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_LongTermDebtMaturitiesRepaymentsOfPrincipal_lbl" xml:lang="en-US">Principal Maturities, Total</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearOne" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearOne" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearOne" xlink:to="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearOne_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearOne_lbl" xml:lang="en-US">Long Term Debt, Amortization And Repayments Of Principal, Year One</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearOne_lbl" xml:lang="en-US">Long Term Debt, Amortization And Repayments Of Principal, Year One</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearOne_lbl" xml:lang="en-US">Total, 2018</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearTwo" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearTwo" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearTwo" xlink:to="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearTwo_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearTwo_lbl" xml:lang="en-US">Long Term Debt, Amortization And Repayments Of Principal, Year Two</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearTwo_lbl" xml:lang="en-US">Long Term Debt, Amortization And Repayments Of Principal, Year Two</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearTwo_lbl" xml:lang="en-US">Total, 2019</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearThree" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearThree" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearThree" xlink:to="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearThree_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearThree_lbl" xml:lang="en-US">Long Term Debt, Amortization And Repayments Of Principal, Year Three</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearThree_lbl" xml:lang="en-US">Long Term Debt, Amortization And Repayments Of Principal, Year Three</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearThree_lbl" xml:lang="en-US">Total, 2020</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearFour" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearFour" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearFour" xlink:to="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearFour_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearFour_lbl" xml:lang="en-US">Long Term Debt, Amortization And Repayments Of Principal, Year Four</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearFour_lbl" xml:lang="en-US">Long Term Debt, Amortization And Repayments Of Principal, Year Four</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearFour_lbl" xml:lang="en-US">Total, 2021</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearFive" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearFive" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearFive" xlink:to="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearFive_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearFive_lbl" xml:lang="en-US">Long Term Debt, Amortization And Repayments Of Principal, Year Five</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearFive_lbl" xml:lang="en-US">Long Term Debt, Amortization And Repayments Of Principal, Year Five</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalYearFive_lbl" xml:lang="en-US">Total, 2022</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalAfterYearFive" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalAfterYearFive" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalAfterYearFive" xlink:to="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalAfterYearFive_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalAfterYearFive_lbl" xml:lang="en-US">Long Term Debt, Amortization And Repayments Of Principal, After Year Five</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalAfterYearFive_lbl" xml:lang="en-US">Long Term Debt, Amortization And Repayments Of Principal, After Year Five</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalAfterYearFive_lbl" xml:lang="en-US">Total, Thereafter</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalGross" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalGross" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalGross" xlink:to="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalGross_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalGross_lbl" xml:lang="en-US">Long Term Debt, Amortization And Repayments Of Principal, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalGross_lbl" xml:lang="en-US">Long Term Debt, Amortization And Repayments Of Principal, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="cli_LongTermDebtAmortizationAndRepaymentsOfPrincipalGross_lbl" xml:lang="en-US">Total, Sub-total</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_lbl" xml:lang="en-US">Debt Instrument, Unamortized Discount (Premium), Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_lbl" xml:lang="en-US">Adjustment for unamortized debt discount/premium, net December 31, 2017</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtInstrumentUnamortizedMarkToMarketPremiumAndPrincipalCosts" xlink:label="cli_DebtInstrumentUnamortizedMarkToMarketPremiumAndPrincipalCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtInstrumentUnamortizedMarkToMarketPremiumAndPrincipalCosts" xlink:to="cli_DebtInstrumentUnamortizedMarkToMarketPremiumAndPrincipalCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtInstrumentUnamortizedMarkToMarketPremiumAndPrincipalCosts_lbl" xml:lang="en-US">Debt Instrument, Unamortized Mark To Market Premium and Principal Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtInstrumentUnamortizedMarkToMarketPremiumAndPrincipalCosts_lbl" xml:lang="en-US">Debt Instrument, Unamortized Mark To Market Premium and Principal Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_DebtInstrumentUnamortizedMarkToMarketPremiumAndPrincipalCosts_lbl" xml:lang="en-US">Total, Unamortized mark to market</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DebtInstrumentUnamortizedPremiumAndPrincipalCosts" xlink:label="cli_DebtInstrumentUnamortizedPremiumAndPrincipalCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DebtInstrumentUnamortizedPremiumAndPrincipalCosts" xlink:to="cli_DebtInstrumentUnamortizedPremiumAndPrincipalCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DebtInstrumentUnamortizedPremiumAndPrincipalCosts_lbl" xml:lang="en-US">Debt Instrument, Unamortized Premium And Principal Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DebtInstrumentUnamortizedPremiumAndPrincipalCosts_lbl" xml:lang="en-US">Debt Instrument, Unamortized Premium And Principal Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:label="cli_DebtInstrumentUnamortizedPremiumAndPrincipalCosts_lbl" xml:lang="en-US">Total, Unamortized deferred financing costs</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="us-gaap_DebtInstrumentFaceAmount" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentFaceAmount" xlink:to="us-gaap_DebtInstrumentFaceAmount_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xml:lang="en-US">Debt Instrument, Face Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xml:lang="en-US">Mortgage payable amount</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfDeferredCompensationArrangementWithIndividualPostretirementBenefitsTable" xlink:label="us-gaap_ScheduleOfDeferredCompensationArrangementWithIndividualPostretirementBenefitsTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDeferredCompensationArrangementWithIndividualPostretirementBenefitsTable" xlink:to="us-gaap_ScheduleOfDeferredCompensationArrangementWithIndividualPostretirementBenefitsTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfDeferredCompensationArrangementWithIndividualPostretirementBenefitsTable_lbl" xml:lang="en-US">Schedule of Deferred Compensation Arrangement with Individual, Postretirement Benefits [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredCompensationArrangementWithIndividualPostretirementBenefitsLineItems" xlink:label="us-gaap_DeferredCompensationArrangementWithIndividualPostretirementBenefitsLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredCompensationArrangementWithIndividualPostretirementBenefitsLineItems" xlink:to="us-gaap_DeferredCompensationArrangementWithIndividualPostretirementBenefitsLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredCompensationArrangementWithIndividualPostretirementBenefitsLineItems_lbl" xml:lang="en-US">Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SavingsRetirementPlanEmployeeMinimumSubscriptionRate" xlink:label="cli_SavingsRetirementPlanEmployeeMinimumSubscriptionRate" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SavingsRetirementPlanEmployeeMinimumSubscriptionRate" xlink:to="cli_SavingsRetirementPlanEmployeeMinimumSubscriptionRate_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SavingsRetirementPlanEmployeeMinimumSubscriptionRate_lbl" xml:lang="en-US">Savings Retirement Plan Employee Minimum Subscription Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SavingsRetirementPlanEmployeeMinimumSubscriptionRate_lbl" xml:lang="en-US">Savings Retirement Plan Employee Minimum Subscription Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SavingsRetirementPlanEmployeeMinimumSubscriptionRate_lbl" xml:lang="en-US">Minimum employee subscription rate, percentage of compensation</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SavingsRetirementPlanEmployeeMaximumSubscriptionRate" xlink:label="cli_SavingsRetirementPlanEmployeeMaximumSubscriptionRate" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SavingsRetirementPlanEmployeeMaximumSubscriptionRate" xlink:to="cli_SavingsRetirementPlanEmployeeMaximumSubscriptionRate_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SavingsRetirementPlanEmployeeMaximumSubscriptionRate_lbl" xml:lang="en-US">Savings Retirement Plan Employee Maximum Subscription Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SavingsRetirementPlanEmployeeMaximumSubscriptionRate_lbl" xml:lang="en-US">Savings Retirement Plan Employee Maximum Subscription Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SavingsRetirementPlanEmployeeMaximumSubscriptionRate_lbl" xml:lang="en-US">Maximum employee subscription rate, percentage of compensation</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EmployeePreTaxContributionsVestedPercent" xlink:label="cli_EmployeePreTaxContributionsVestedPercent" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EmployeePreTaxContributionsVestedPercent" xlink:to="cli_EmployeePreTaxContributionsVestedPercent_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EmployeePreTaxContributionsVestedPercent_lbl" xml:lang="en-US">Employee pre-tax contributions vested percent.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EmployeePreTaxContributionsVestedPercent_lbl" xml:lang="en-US">Employee Pre Tax Contributions Vested Percent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_EmployeePreTaxContributionsVestedPercent_lbl" xml:lang="en-US">Employee pre-tax contributions vested percentage</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SavingsRetirementPlanVestingPeriod" xlink:label="cli_SavingsRetirementPlanVestingPeriod" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SavingsRetirementPlanVestingPeriod" xlink:to="cli_SavingsRetirementPlanVestingPeriod_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SavingsRetirementPlanVestingPeriod_lbl" xml:lang="en-US">Savings Retirement Plan Vesting Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SavingsRetirementPlanVestingPeriod_lbl" xml:lang="en-US">Savings Retirement Plan Vesting Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SavingsRetirementPlanVestingPeriod_lbl" xml:lang="en-US">Employer contribution vesting period</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_VestingRate" xlink:label="cli_VestingRate" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_VestingRate" xlink:to="cli_VestingRate_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_VestingRate_lbl" xml:lang="en-US">Vesting rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_VestingRate_lbl" xml:lang="en-US">Vesting Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_VestingRate_lbl" xml:lang="en-US">Vesting rate</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PercentVestedAfterTotalServicePeriod" xlink:label="cli_PercentVestedAfterTotalServicePeriod" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PercentVestedAfterTotalServicePeriod" xlink:to="cli_PercentVestedAfterTotalServicePeriod_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PercentVestedAfterTotalServicePeriod_lbl" xml:lang="en-US">Percent vested after total service period.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PercentVestedAfterTotalServicePeriod_lbl" xml:lang="en-US">Percent Vested After Total Service Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PercentVestedAfterTotalServicePeriod_lbl" xml:lang="en-US">Percentage vested after total service period</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SavingsRetirementPlanVestingRights" xlink:label="cli_SavingsRetirementPlanVestingRights" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SavingsRetirementPlanVestingRights" xlink:to="cli_SavingsRetirementPlanVestingRights_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SavingsRetirementPlanVestingRights_lbl" xml:lang="en-US">Savings Retirement Plan Vesting Rights</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SavingsRetirementPlanVestingRights_lbl" xml:lang="en-US">Savings Retirement Plan Vesting Rights</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SavingsRetirementPlanVestingRights_lbl" xml:lang="en-US">Employees' vesting rights</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeBenefitsAndShareBasedCompensation" xlink:label="us-gaap_EmployeeBenefitsAndShareBasedCompensation" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeBenefitsAndShareBasedCompensation" xlink:to="us-gaap_EmployeeBenefitsAndShareBasedCompensation_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeBenefitsAndShareBasedCompensation_lbl" xml:lang="en-US">Employee Benefits and Share-based Compensation</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EmployeeBenefitsAndShareBasedCompensation_lbl" xml:lang="en-US">Expenses for employee benefit plan</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueInputsAssetsQuantitativeInformationTable" xlink:label="us-gaap_FairValueInputsAssetsQuantitativeInformationTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsAssetsQuantitativeInformationTable" xlink:to="us-gaap_FairValueInputsAssetsQuantitativeInformationTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueInputsAssetsQuantitativeInformationTable_lbl" xml:lang="en-US">Fair Value Inputs, Assets, Quantitative Information [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueInputsAssetsQuantitativeInformationLineItems" xlink:label="us-gaap_FairValueInputsAssetsQuantitativeInformationLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsAssetsQuantitativeInformationLineItems" xlink:to="us-gaap_FairValueInputsAssetsQuantitativeInformationLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueInputsAssetsQuantitativeInformationLineItems_lbl" xml:lang="en-US">Fair Value Inputs, Assets, Quantitative Information [Line Items]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentFairValue" xlink:label="us-gaap_DebtInstrumentFairValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentFairValue" xlink:to="us-gaap_DebtInstrumentFairValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentFairValue_lbl" xml:lang="en-US">Debt Instrument, Fair Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DebtInstrumentFairValue_lbl" xml:lang="en-US">Fair value of Company's long-term debt</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment_lbl" xml:lang="en-US">Assets Held-for-sale, Property, Plant and Equipment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment_lbl" xml:lang="en-US">Aggregate carrying value</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_HarborsideFinancialCenterPlazaFouraMember" xlink:label="cli_HarborsideFinancialCenterPlazaFouraMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_HarborsideFinancialCenterPlazaFouraMember" xlink:to="cli_HarborsideFinancialCenterPlazaFouraMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_HarborsideFinancialCenterPlazaFouraMember_lbl" xml:lang="en-US">Harborside Financial Center Plaza 4-A [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_HarborsideFinancialCenterPlazaFouraMember_lbl" xml:lang="en-US">Harborside Financial Center Plaza Foura [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_HarborsideFinancialCenterPlazaFouraMember_lbl" xml:lang="en-US">Harborside Plaza 4-A [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_HarborsideFinancialCenterPlazaFiveMember" xlink:label="cli_HarborsideFinancialCenterPlazaFiveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_HarborsideFinancialCenterPlazaFiveMember" xlink:to="cli_HarborsideFinancialCenterPlazaFiveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_HarborsideFinancialCenterPlazaFiveMember_lbl" xml:lang="en-US">Harborside Financial Center Plaza 5 [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_HarborsideFinancialCenterPlazaFiveMember_lbl" xml:lang="en-US">Harborside Financial Center Plaza Five [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_HarborsideFinancialCenterPlazaFiveMember_lbl" xml:lang="en-US">Harborside Plaza 5 [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PortImperialFourAndFiveGarageDevelopmentMember" xlink:label="cli_PortImperialFourAndFiveGarageDevelopmentMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PortImperialFourAndFiveGarageDevelopmentMember" xlink:to="cli_PortImperialFourAndFiveGarageDevelopmentMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PortImperialFourAndFiveGarageDevelopmentMember_lbl" xml:lang="en-US">Port Imperial 4/5 Garage Development [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PortImperialFourAndFiveGarageDevelopmentMember_lbl" xml:lang="en-US">Port Imperial Four And Five Garage Development [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PortImperialFourAndFiveGarageDevelopmentMember_lbl" xml:lang="en-US">Port Imperial South 4/5 Garage [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PortImperialSouthOneThirdGarageDevelopmentMember" xlink:label="cli_PortImperialSouthOneThirdGarageDevelopmentMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PortImperialSouthOneThirdGarageDevelopmentMember" xlink:to="cli_PortImperialSouthOneThirdGarageDevelopmentMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PortImperialSouthOneThirdGarageDevelopmentMember_lbl" xml:lang="en-US">Port Imperial South One Third Garage Development [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PortImperialSouthOneThirdGarageDevelopmentMember_lbl" xml:lang="en-US">Port Imperial South One Third Garage Development [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PortImperialSouthOneThirdGarageDevelopmentMember_lbl" xml:lang="en-US">Port Imperial South 1/3 Garage [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ProjectTerm" xlink:label="cli_ProjectTerm" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ProjectTerm" xlink:to="cli_ProjectTerm_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ProjectTerm_lbl" xml:lang="en-US">Project Term</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ProjectTerm_lbl" xml:lang="en-US">Project Term</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ProjectTerm_lbl" xml:lang="en-US">Project period</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost" xlink:label="cli_PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost" xlink:to="cli_PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost_lbl" xml:lang="en-US">Payments in Lieu of Property Tax As Percentage of Total Project Cost</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost_lbl" xml:lang="en-US">Payments in Lieu of Property Tax As Percentage of Total Project Cost</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PaymentsInLieuOfPropertyTaxAsPercentageOfTotalProjectCost_lbl" xml:lang="en-US">Percentage of PILOT on project costs</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EstimatedCostOfProject" xlink:label="cli_EstimatedCostOfProject" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EstimatedCostOfProject" xlink:to="cli_EstimatedCostOfProject_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EstimatedCostOfProject_lbl" xml:lang="en-US">Estimated Cost Of Project</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EstimatedCostOfProject_lbl" xml:lang="en-US">Estimated Cost Of Project</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_EstimatedCostOfProject_lbl" xml:lang="en-US">Total project costs</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PaymentsInLieuOfPropertyTaxes" xlink:label="cli_PaymentsInLieuOfPropertyTaxes" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PaymentsInLieuOfPropertyTaxes" xlink:to="cli_PaymentsInLieuOfPropertyTaxes_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PaymentsInLieuOfPropertyTaxes_lbl" xml:lang="en-US">Payments In Lieu Of Property Taxes</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PaymentsInLieuOfPropertyTaxes_lbl" xml:lang="en-US">Payments In Lieu Of Property Taxes</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PaymentsInLieuOfPropertyTaxes_lbl" xml:lang="en-US">Payments in lieu of property taxes (PILOT)</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PaymentsInLieuOfPropertyTaxesAnnualPayment" xlink:label="cli_PaymentsInLieuOfPropertyTaxesAnnualPayment" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PaymentsInLieuOfPropertyTaxesAnnualPayment" xlink:to="cli_PaymentsInLieuOfPropertyTaxesAnnualPayment_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PaymentsInLieuOfPropertyTaxesAnnualPayment_lbl" xml:lang="en-US">Payments In Lieu Of Property Taxes, Annual Payment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PaymentsInLieuOfPropertyTaxesAnnualPayment_lbl" xml:lang="en-US">Payments In Lieu Of Property Taxes, Annual Payment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PaymentsInLieuOfPropertyTaxesAnnualPayment_lbl" xml:lang="en-US">Annual Payments in lieu of property taxes (PILOT)</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PaymentsInLieuOfPropertyTaxAsPercentageBasedOnLandValue" xlink:label="cli_PaymentsInLieuOfPropertyTaxAsPercentageBasedOnLandValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PaymentsInLieuOfPropertyTaxAsPercentageBasedOnLandValue" xlink:to="cli_PaymentsInLieuOfPropertyTaxAsPercentageBasedOnLandValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PaymentsInLieuOfPropertyTaxAsPercentageBasedOnLandValue_lbl" xml:lang="en-US">Payments In Lieu Of Property Tax As Percentage Based On The Land Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PaymentsInLieuOfPropertyTaxAsPercentageBasedOnLandValue_lbl" xml:lang="en-US">Payments In Lieu Of Property Tax As Percentage Based On Land Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PaymentsInLieuOfPropertyTaxAsPercentageBasedOnLandValue_lbl" xml:lang="en-US">Percentage of taxes paid based on the land value</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AnnualPercentageOfCostForPhaseIn" xlink:label="cli_AnnualPercentageOfCostForPhaseIn" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AnnualPercentageOfCostForPhaseIn" xlink:to="cli_AnnualPercentageOfCostForPhaseIn_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AnnualPercentageOfCostForPhaseIn_lbl" xml:lang="en-US">Annual Percentage Of Cost For Phase In</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AnnualPercentageOfCostForPhaseIn_lbl" xml:lang="en-US">Annual Percentage Of Cost For Phase In</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AnnualPercentageOfCostForPhaseIn_lbl" xml:lang="en-US">Annual percentage of cost for phase in</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PaymentsInLieuOfPropertyTaxAsPercentageOfGrossRevenues" xlink:label="cli_PaymentsInLieuOfPropertyTaxAsPercentageOfGrossRevenues" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PaymentsInLieuOfPropertyTaxAsPercentageOfGrossRevenues" xlink:to="cli_PaymentsInLieuOfPropertyTaxAsPercentageOfGrossRevenues_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PaymentsInLieuOfPropertyTaxAsPercentageOfGrossRevenues_lbl" xml:lang="en-US">Payments In Lieu Of Property Tax As Percentage Of Gross Revenues</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PaymentsInLieuOfPropertyTaxAsPercentageOfGrossRevenues_lbl" xml:lang="en-US">Payments In Lieu Of Property Tax As Percentage Of Gross Revenues</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PaymentsInLieuOfPropertyTaxAsPercentageOfGrossRevenues_lbl" xml:lang="en-US">Percentage of PILOT on gross revenues</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OperatingLeaseExpenseIncludingSubleaseRentals" xlink:label="cli_OperatingLeaseExpenseIncludingSubleaseRentals" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OperatingLeaseExpenseIncludingSubleaseRentals" xlink:to="cli_OperatingLeaseExpenseIncludingSubleaseRentals_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OperatingLeaseExpenseIncludingSubleaseRentals_lbl" xml:lang="en-US">Operating Lease, Expense, Including Sublease Rentals</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OperatingLeaseExpenseIncludingSubleaseRentals_lbl" xml:lang="en-US">Operating Lease, Expense, Including Sublease Rentals</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OperatingLeaseExpenseIncludingSubleaseRentals_lbl" xml:lang="en-US">Ground lease expense incurred</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DevelopmentPropertyMember" xlink:label="cli_DevelopmentPropertyMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DevelopmentPropertyMember" xlink:to="cli_DevelopmentPropertyMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DevelopmentPropertyMember_lbl" xml:lang="en-US">Development Property [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DevelopmentPropertyMember_lbl" xml:lang="en-US">Development Property [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DevelopmentPropertyMember_lbl" xml:lang="en-US">Development Property [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PropertyNetBookValue" xlink:label="cli_PropertyNetBookValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PropertyNetBookValue" xlink:to="cli_PropertyNetBookValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PropertyNetBookValue_lbl" xml:lang="en-US">Property Net Book Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PropertyNetBookValue_lbl" xml:lang="en-US">Property Net Book Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PropertyNetBookValue_lbl" xml:lang="en-US">Properties aggregate net book value</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConstructionAndDevelopmentCosts" xlink:label="us-gaap_ConstructionAndDevelopmentCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConstructionAndDevelopmentCosts" xlink:to="us-gaap_ConstructionAndDevelopmentCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConstructionAndDevelopmentCosts_lbl" xml:lang="en-US">Construction and Development Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConstructionAndDevelopmentCosts_lbl" xml:lang="en-US">Costs of the project incurred</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DeliveryDateOfConstructedBuilding" xlink:label="cli_DeliveryDateOfConstructedBuilding" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DeliveryDateOfConstructedBuilding" xlink:to="cli_DeliveryDateOfConstructedBuilding_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DeliveryDateOfConstructedBuilding_lbl" xml:lang="en-US">Delivery date of constructed building</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DeliveryDateOfConstructedBuilding_lbl" xml:lang="en-US">Delivery Date Of Constructed Building</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DeliveryDateOfConstructedBuilding_lbl" xml:lang="en-US">Delivery date to tenant</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AmountToFund" xlink:label="cli_AmountToFund" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AmountToFund" xlink:to="cli_AmountToFund_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AmountToFund_lbl" xml:lang="en-US">Amount To Fund</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AmountToFund_lbl" xml:lang="en-US">Amount To Fund</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AmountToFund_lbl" xml:lang="en-US">Amount to fund</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SeveranceCosts1" xlink:label="us-gaap_SeveranceCosts1" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SeveranceCosts1" xlink:to="us-gaap_SeveranceCosts1_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SeveranceCosts1_lbl" xml:lang="en-US">Severance Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SeveranceCosts1_lbl" xml:lang="en-US">Severance benefits</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AnnualBonusOpportunityAmountProratedPortion" xlink:label="cli_AnnualBonusOpportunityAmountProratedPortion" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AnnualBonusOpportunityAmountProratedPortion" xlink:to="cli_AnnualBonusOpportunityAmountProratedPortion_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AnnualBonusOpportunityAmountProratedPortion_lbl" xml:lang="en-US">Annual Bonus Opportunity Amount, Prorated Portion</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AnnualBonusOpportunityAmountProratedPortion_lbl" xml:lang="en-US">Annual Bonus Opportunity Amount, Prorated Portion</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AnnualBonusOpportunityAmountProratedPortion_lbl" xml:lang="en-US">Prorated 2018 target bonus amount</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PeriodForContinuationOfHealthInsurance" xlink:label="cli_PeriodForContinuationOfHealthInsurance" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PeriodForContinuationOfHealthInsurance" xlink:to="cli_PeriodForContinuationOfHealthInsurance_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PeriodForContinuationOfHealthInsurance_lbl" xml:lang="en-US">Period For Continuation Of Health Insurance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PeriodForContinuationOfHealthInsurance_lbl" xml:lang="en-US">Period For Continuation Of Health Insurance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PeriodForContinuationOfHealthInsurance_lbl" xml:lang="en-US">Period for continuation of health insurance</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SupplementalUnemploymentBenefitsContinuationOfHealthCare" xlink:label="us-gaap_SupplementalUnemploymentBenefitsContinuationOfHealthCare" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplementalUnemploymentBenefitsContinuationOfHealthCare" xlink:to="us-gaap_SupplementalUnemploymentBenefitsContinuationOfHealthCare_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SupplementalUnemploymentBenefitsContinuationOfHealthCare_lbl" xml:lang="en-US">Supplemental Unemployment Benefits, Continuation of Health Care</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SupplementalUnemploymentBenefitsContinuationOfHealthCare_lbl" xml:lang="en-US">COBRA payment</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAcceleratedVestingNumber" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAcceleratedVestingNumber" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAcceleratedVestingNumber" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAcceleratedVestingNumber_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAcceleratedVestingNumber_lbl" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Accelerated Vesting, Number</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAcceleratedVestingNumber_lbl" xml:lang="en-US">Accelerated vesting shares</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardPartialAcceleratedVestingNumber" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardPartialAcceleratedVestingNumber" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardPartialAcceleratedVestingNumber" xlink:to="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardPartialAcceleratedVestingNumber_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardPartialAcceleratedVestingNumber_lbl" xml:lang="en-US">Share-based Compensation Arrangement By Share-based Payment Award, Partial Accelerated Vesting, Number</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardPartialAcceleratedVestingNumber_lbl" xml:lang="en-US">Share-based Compensation Arrangement By Share-based Payment Award, Partial Accelerated Vesting, Number</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardPartialAcceleratedVestingNumber_lbl" xml:lang="en-US">Partial accelerated vesting shares</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PropertyLockUpsExpiredMember" xlink:label="cli_PropertyLockUpsExpiredMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PropertyLockUpsExpiredMember" xlink:to="cli_PropertyLockUpsExpiredMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PropertyLockUpsExpiredMember_lbl" xml:lang="en-US">Property Lock-Ups Expired [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PropertyLockUpsExpiredMember_lbl" xml:lang="en-US">Property Lock Ups Expired [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PropertyLockUpsExpiredMember_lbl" xml:lang="en-US">Property Lock-Ups Expired [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent_lbl" xml:lang="en-US">Operating Leases, Future Minimum Payments Due, Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent_lbl" xml:lang="en-US">2018</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_lbl" xml:lang="en-US">Operating Leases, Future Minimum Payments, Due in Two Years</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_lbl" xml:lang="en-US">2019</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears_lbl" xml:lang="en-US">Operating Leases, Future Minimum Payments, Due in Three Years</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears_lbl" xml:lang="en-US">2020</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears_lbl" xml:lang="en-US">Operating Leases, Future Minimum Payments, Due in Four Years</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears_lbl" xml:lang="en-US">2021</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears_lbl" xml:lang="en-US">Operating Leases, Future Minimum Payments, Due in Five Years</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears_lbl" xml:lang="en-US">2022</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter_lbl" xml:lang="en-US">Operating Leases, Future Minimum Payments, Due Thereafter</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter_lbl" xml:lang="en-US">2023 through 2084</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDue_lbl" xml:lang="en-US">Operating Leases, Future Minimum Payments Due</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDue_lbl" xml:lang="en-US">Total</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable" xlink:label="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable" xlink:to="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable_lbl" xml:lang="en-US">Property Subject to or Available for Operating Lease, by Major Property Class [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis" xlink:label="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis" xlink:to="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis_lbl" xml:lang="en-US">Property Subject to or Available for Operating Lease [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" xlink:label="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" xlink:to="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_lbl" xml:lang="en-US">Property Subject To Or Available For Operating Lease [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_lbl" xml:lang="en-US">Property Subject to or Available for Operating Lease [Domain]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TenantLeasesMember" xlink:label="cli_TenantLeasesMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TenantLeasesMember" xlink:to="cli_TenantLeasesMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TenantLeasesMember_lbl" xml:lang="en-US">Tenant Leases [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TenantLeasesMember_lbl" xml:lang="en-US">Tenant Leases [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TenantLeasesMember_lbl" xml:lang="en-US">Tenant Leases [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseLineItems" xlink:label="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseLineItems" xlink:to="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseLineItems_lbl" xml:lang="en-US">Property Subject to or Available for Operating Lease [Line Items]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableCurrent" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableCurrent" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableCurrent" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableCurrent_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableCurrent_lbl" xml:lang="en-US">Operating Leases, Future Minimum Payments Receivable, Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableCurrent_lbl" xml:lang="en-US">2018</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInTwoYears" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInTwoYears" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInTwoYears" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInTwoYears_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInTwoYears_lbl" xml:lang="en-US">Operating Leases, Future Minimum Payments Receivable, in Two Years</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInTwoYears_lbl" xml:lang="en-US">2019</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInThreeYears" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInThreeYears" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInThreeYears" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInThreeYears_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInThreeYears_lbl" xml:lang="en-US">Operating Leases, Future Minimum Payments Receivable, in Three Years</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInThreeYears_lbl" xml:lang="en-US">2020</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFourYears" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFourYears" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFourYears" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFourYears_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFourYears_lbl" xml:lang="en-US">Operating Leases, Future Minimum Payments Receivable, in Four Years</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFourYears_lbl" xml:lang="en-US">2021</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFiveYears" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFiveYears" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFiveYears" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFiveYears_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFiveYears_lbl" xml:lang="en-US">Operating Leases, Future Minimum Payments Receivable, in Five Years</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFiveYears_lbl" xml:lang="en-US">2022</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableThereafter" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableThereafter" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableThereafter" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableThereafter_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableThereafter_lbl" xml:lang="en-US">Operating Leases, Future Minimum Payments Receivable, Thereafter</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableThereafter_lbl" xml:lang="en-US">2023 and thereafter</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsReceivable" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivable" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivable_lbl" xml:lang="en-US">Operating Leases, Future Minimum Payments Receivable</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsReceivable_lbl" xml:lang="en-US">Total</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LeaseExpirationDate1" xlink:label="us-gaap_LeaseExpirationDate1" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseExpirationDate1" xlink:to="us-gaap_LeaseExpirationDate1_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LeaseExpirationDate1_lbl" xml:lang="en-US">Lease Expiration Date</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LeaseExpirationDate1_lbl" xml:lang="en-US">Operating leases with various expiration dates through year</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LeasePeriod" xlink:label="cli_LeasePeriod" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LeasePeriod" xlink:to="cli_LeasePeriod_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LeasePeriod_lbl" xml:lang="en-US">Lease Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LeasePeriod_lbl" xml:lang="en-US">Lease Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_LeasePeriod_lbl" xml:lang="en-US">Lease period</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ContributedEquityValue" xlink:label="cli_ContributedEquityValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ContributedEquityValue" xlink:to="cli_ContributedEquityValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ContributedEquityValue_lbl" xml:lang="en-US">Contributed Equity Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ContributedEquityValue_lbl" xml:lang="en-US">Contributed Equity Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ContributedEquityValue_lbl" xml:lang="en-US">Contributed equity value</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AnnualReturnFromCashFlowOperations" xlink:label="cli_AnnualReturnFromCashFlowOperations" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AnnualReturnFromCashFlowOperations" xlink:to="cli_AnnualReturnFromCashFlowOperations_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AnnualReturnFromCashFlowOperations_lbl" xml:lang="en-US">Annual Return From Cash Flow Operations</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AnnualReturnFromCashFlowOperations_lbl" xml:lang="en-US">Annual Return From Cash Flow Operations</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AnnualReturnFromCashFlowOperations_lbl" xml:lang="en-US">Annual return</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AnnualReturnOnEquityValue" xlink:label="cli_AnnualReturnOnEquityValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AnnualReturnOnEquityValue" xlink:to="cli_AnnualReturnOnEquityValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AnnualReturnOnEquityValue_lbl" xml:lang="en-US">Annual Return On The Equity Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AnnualReturnOnEquityValue_lbl" xml:lang="en-US">Annual Return On The Equity Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AnnualReturnOnEquityValue_lbl" xml:lang="en-US">Annual return on the equity value</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AnnualReturnOnEquityValueBaseReturn" xlink:label="cli_AnnualReturnOnEquityValueBaseReturn" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AnnualReturnOnEquityValueBaseReturn" xlink:to="cli_AnnualReturnOnEquityValueBaseReturn_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AnnualReturnOnEquityValueBaseReturn_lbl" xml:lang="en-US">Annual Return On The Equity Value, Base Return</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AnnualReturnOnEquityValueBaseReturn_lbl" xml:lang="en-US">Annual Return On The Equity Value, Base Return</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AnnualReturnOnEquityValueBaseReturn_lbl" xml:lang="en-US">Base return</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ProRataDistributionPercent" xlink:label="cli_ProRataDistributionPercent" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ProRataDistributionPercent" xlink:to="cli_ProRataDistributionPercent_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ProRataDistributionPercent_lbl" xml:lang="en-US">Pro Rata Distribution Percent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ProRataDistributionPercent_lbl" xml:lang="en-US">Pro Rata Distribution Percent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ProRataDistributionPercent_lbl" xml:lang="en-US">Pro rata distribution</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_InternalRateOfReturnPercent" xlink:label="cli_InternalRateOfReturnPercent" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_InternalRateOfReturnPercent" xlink:to="cli_InternalRateOfReturnPercent_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_InternalRateOfReturnPercent_lbl" xml:lang="en-US">Internal Rate of Return Percent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_InternalRateOfReturnPercent_lbl" xml:lang="en-US">Internal Rate of Return Percent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_InternalRateOfReturnPercent_lbl" xml:lang="en-US">Internal rate of return</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ProRataDistributionPercentCashFlowFromCapitalEvents" xlink:label="cli_ProRataDistributionPercentCashFlowFromCapitalEvents" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ProRataDistributionPercentCashFlowFromCapitalEvents" xlink:to="cli_ProRataDistributionPercentCashFlowFromCapitalEvents_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ProRataDistributionPercentCashFlowFromCapitalEvents_lbl" xml:lang="en-US">Pro Rata Distribution Percent, Cash Flow From Capital Events</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ProRataDistributionPercentCashFlowFromCapitalEvents_lbl" xml:lang="en-US">Pro Rata Distribution Percent, Cash Flow From Capital Events</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ProRataDistributionPercentCashFlowFromCapitalEvents_lbl" xml:lang="en-US">Pro rata share</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="us-gaap_PreferredStockSharesIssued" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesIssued" xlink:to="us-gaap_PreferredStockSharesIssued_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockSharesIssued_lbl" xml:lang="en-US">Preferred Stock, Shares Issued</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredStockSharesIssued_lbl" xml:lang="en-US">Preferred stock shares issued</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ConvertiblePreferredUnitSharesIssuedUponConversion" xlink:label="cli_ConvertiblePreferredUnitSharesIssuedUponConversion" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ConvertiblePreferredUnitSharesIssuedUponConversion" xlink:to="cli_ConvertiblePreferredUnitSharesIssuedUponConversion_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ConvertiblePreferredUnitSharesIssuedUponConversion_lbl" xml:lang="en-US">Convertible Preferred Unit, Shares Issued Upon Conversion</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ConvertiblePreferredUnitSharesIssuedUponConversion_lbl" xml:lang="en-US">Convertible Preferred Unit, Shares Issued Upon Conversion</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ConvertiblePreferredUnitSharesIssuedUponConversion_lbl" xml:lang="en-US">Convertible preferred units</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_lbl" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_lbl" xml:lang="en-US">Exercisable period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_lbl" xml:lang="en-US">Expiration period</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConversionOfStockSharesConverted1" xlink:label="us-gaap_ConversionOfStockSharesConverted1" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConversionOfStockSharesConverted1" xlink:to="us-gaap_ConversionOfStockSharesConverted1_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConversionOfStockSharesConverted1_lbl" xml:lang="en-US">Conversion of Stock, Shares Converted</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConversionOfStockSharesConverted1_lbl" xml:lang="en-US">Shares converted to common units</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CommonUnitDistributionsPerUnitDeclared" xlink:label="cli_CommonUnitDistributionsPerUnitDeclared" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CommonUnitDistributionsPerUnitDeclared" xlink:to="cli_CommonUnitDistributionsPerUnitDeclared_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CommonUnitDistributionsPerUnitDeclared_lbl" xml:lang="en-US">Common Unit Distributions Per Unit Declared</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CommonUnitDistributionsPerUnitDeclared_lbl" xml:lang="en-US">Common Unit Distributions Per Unit Declared</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_CommonUnitDistributionsPerUnitDeclared_lbl" xml:lang="en-US">Common unit distribution per unit declared</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_CommonUnitDistributionsPerUnitDeclared_lbl" xml:lang="en-US">Distribution declared per common unit</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NoncontrollingInterestEstimatedRedemptionValue" xlink:label="cli_NoncontrollingInterestEstimatedRedemptionValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NoncontrollingInterestEstimatedRedemptionValue" xlink:to="cli_NoncontrollingInterestEstimatedRedemptionValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NoncontrollingInterestEstimatedRedemptionValue_lbl" xml:lang="en-US">Noncontrolling Interest, Estimated Redemption Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NoncontrollingInterestEstimatedRedemptionValue_lbl" xml:lang="en-US">Noncontrolling Interest, Estimated Redemption Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NoncontrollingInterestEstimatedRedemptionValue_lbl" xml:lang="en-US">Estimated redemption value</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TemporaryEquityStockIssuedDuringPeriodValueGross" xlink:label="cli_TemporaryEquityStockIssuedDuringPeriodValueGross" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TemporaryEquityStockIssuedDuringPeriodValueGross" xlink:to="cli_TemporaryEquityStockIssuedDuringPeriodValueGross_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TemporaryEquityStockIssuedDuringPeriodValueGross_lbl" xml:lang="en-US">Temporary Equity, Stock Issued During Period, Value, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TemporaryEquityStockIssuedDuringPeriodValueGross_lbl" xml:lang="en-US">Temporary Equity, Stock Issued During Period, Value, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TemporaryEquityStockIssuedDuringPeriodValueGross_lbl" xml:lang="en-US">Redeemable Noncontrolling Interests Issued</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RedeemableNoncontrollingInterestIssuanceCosts" xlink:label="cli_RedeemableNoncontrollingInterestIssuanceCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RedeemableNoncontrollingInterestIssuanceCosts" xlink:to="cli_RedeemableNoncontrollingInterestIssuanceCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RedeemableNoncontrollingInterestIssuanceCosts_lbl" xml:lang="en-US">Redeemable Noncontrolling Interest Issuance Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RedeemableNoncontrollingInterestIssuanceCosts_lbl" xml:lang="en-US">Redeemable Noncontrolling Interest Issuance Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RedeemableNoncontrollingInterestIssuanceCosts_lbl" xml:lang="en-US">Issuance Costs</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues" xlink:label="us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues" xlink:to="us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues_lbl" xml:lang="en-US">Temporary Equity, Stock Issued During Period, Value, New Issues</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues_lbl" xml:lang="en-US">Net</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RedeemableNoncontrollingInterestDecreaseFromDistribution" xlink:label="cli_RedeemableNoncontrollingInterestDecreaseFromDistribution" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RedeemableNoncontrollingInterestDecreaseFromDistribution" xlink:to="cli_RedeemableNoncontrollingInterestDecreaseFromDistribution_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RedeemableNoncontrollingInterestDecreaseFromDistribution_lbl" xml:lang="en-US">Redeemable Noncontrolling Interest Decrease From Distribution</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RedeemableNoncontrollingInterestDecreaseFromDistribution_lbl" xml:lang="en-US">Redeemable Noncontrolling Interest Decrease From Distribution</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_RedeemableNoncontrollingInterestDecreaseFromDistribution_lbl" xml:lang="en-US">Distributions</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DateShareRepurchaseProgramInitiation" xlink:label="cli_DateShareRepurchaseProgramInitiation" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DateShareRepurchaseProgramInitiation" xlink:to="cli_DateShareRepurchaseProgramInitiation_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DateShareRepurchaseProgramInitiation_lbl" xml:lang="en-US">Date Share Repurchase Program was initiated.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DateShareRepurchaseProgramInitiation_lbl" xml:lang="en-US">Date Share Repurchase Program Initiation</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_DateShareRepurchaseProgramInitiation_lbl" xml:lang="en-US">Date share repurchase program was initiated</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchaseProgramAuthorizedAmount1" xlink:label="us-gaap_StockRepurchaseProgramAuthorizedAmount1" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockRepurchaseProgramAuthorizedAmount1" xlink:to="us-gaap_StockRepurchaseProgramAuthorizedAmount1_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockRepurchaseProgramAuthorizedAmount1_lbl" xml:lang="en-US">Stock Repurchase Program Authorized Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockRepurchaseProgramAuthorizedAmount1_lbl" xml:lang="en-US">Capacity of share repurchase program</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares" xlink:label="us-gaap_StockRepurchasedAndRetiredDuringPeriodShares" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockRepurchasedAndRetiredDuringPeriodShares" xlink:to="us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_lbl" xml:lang="en-US">Stock Repurchased and Retired During Period, Shares</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_lbl" xml:lang="en-US">Shares purchased and retired</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsForRepurchaseOfEquity" xlink:label="us-gaap_PaymentsForRepurchaseOfEquity" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsForRepurchaseOfEquity" xlink:to="us-gaap_PaymentsForRepurchaseOfEquity_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsForRepurchaseOfEquity_lbl" xml:lang="en-US">Payments for Repurchase of Equity</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PaymentsForRepurchaseOfEquity_lbl" xml:lang="en-US">Aggregate cost of stock repurchased</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1" xlink:label="us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1" xlink:to="us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_lbl" xml:lang="en-US">Stock Repurchase Program Remaining Authorized Repurchase Amount</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfCommonLimitedPartnersUnits" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonLimitedPartnersUnits_lbl" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonLimitedPartnersUnits_lbl" xml:lang="en-US">Proceeds from sale of common units</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:to="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xml:lang="en-US">Common stock reserved for future issuance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xml:lang="en-US">Reserved stocks for issuance</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MonthlyCashInvestmentWithoutRestrictionMaximum" xlink:label="cli_MonthlyCashInvestmentWithoutRestrictionMaximum" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MonthlyCashInvestmentWithoutRestrictionMaximum" xlink:to="cli_MonthlyCashInvestmentWithoutRestrictionMaximum_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MonthlyCashInvestmentWithoutRestrictionMaximum_lbl" xml:lang="en-US">Monthly cash investment without restriction, maximum.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MonthlyCashInvestmentWithoutRestrictionMaximum_lbl" xml:lang="en-US">Monthly Cash Investment Without Restriction Maximum</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MonthlyCashInvestmentWithoutRestrictionMaximum_lbl" xml:lang="en-US">Monthly cash investment without restriction, maximum</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" xml:lang="en-US">Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="us-gaap_PlanNameAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PlanNameAxis_lbl" xml:lang="en-US">Plan Name [Axis]</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameDomain" xlink:to="us-gaap_PlanNameDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PlanNameDomain_lbl" xml:lang="en-US">Plan Name [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PlanNameDomain_lbl" xml:lang="en-US">Plan Name [Domain]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoThousandThirteenIncentiveStockPlanMember" xlink:label="cli_TwoThousandThirteenIncentiveStockPlanMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoThousandThirteenIncentiveStockPlanMember" xlink:to="cli_TwoThousandThirteenIncentiveStockPlanMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoThousandThirteenIncentiveStockPlanMember_lbl" xml:lang="en-US">2013 Incentive Stock Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoThousandThirteenIncentiveStockPlanMember_lbl" xml:lang="en-US">Two Thousand Thirteen Incentive Stock Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoThousandThirteenIncentiveStockPlanMember_lbl" xml:lang="en-US">2013 Incentive Stock Plan [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award [Line Items]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_lbl" xml:lang="en-US">Stock compensation vesting period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_lbl" xml:lang="en-US">Exercisable time period</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageRemainingContractualTerm2" xlink:label="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageRemainingContractualTerm2" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageRemainingContractualTerm2" xlink:to="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageRemainingContractualTerm2_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageRemainingContractualTerm2_lbl" xml:lang="en-US">Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Remaining Contractual Term</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageRemainingContractualTerm2_lbl" xml:lang="en-US">Weighted average remaining contractual life</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharePrice" xlink:label="us-gaap_SharePrice" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharePrice" xlink:to="us-gaap_SharePrice_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharePrice_lbl" xml:lang="en-US">Share price</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US">Share price - weighted average fair value of options granted</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="us-gaap_ProceedsFromStockOptionsExercised" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromStockOptionsExercised" xlink:to="us-gaap_ProceedsFromStockOptionsExercised_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromStockOptionsExercised_lbl" xml:lang="en-US">Proceeds from stock options exercised</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockOptionPlanExpense" xlink:label="us-gaap_StockOptionPlanExpense" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockOptionPlanExpense" xlink:to="us-gaap_StockOptionPlanExpense_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockOptionPlanExpense_lbl" xml:lang="en-US">Stock or Unit Option Plan Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockOptionPlanExpense_lbl" xml:lang="en-US">Stock options expense</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xml:lang="en-US">Shares Under Options - Granted</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xml:lang="en-US">Shares granted</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdSharePriceTrigger" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdSharePriceTrigger" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdSharePriceTrigger" xlink:to="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdSharePriceTrigger_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdSharePriceTrigger_lbl" xml:lang="en-US">Share Based Compensation Arrangement By Share-based Payment Award Threshold Share Price Trigger</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdSharePriceTrigger_lbl" xml:lang="en-US">Share Based Compensation Arrangement By Share-based Payment Award Threshold Share Price Trigger</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdSharePriceTrigger_lbl" xml:lang="en-US">Common stock trade share price</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingInstallmentTerm" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingInstallmentTerm" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingInstallmentTerm" xlink:to="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingInstallmentTerm_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingInstallmentTerm_lbl" xml:lang="en-US">Share Based Compensation Arrangement By Share-based Payment Award Vesting Installment Term</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingInstallmentTerm_lbl" xml:lang="en-US">Share Based Compensation Arrangement By Share-based Payment Award Vesting Installment Term</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingInstallmentTerm_lbl" xml:lang="en-US">Annual installments</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdTradingDays" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdTradingDays" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdTradingDays" xlink:to="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdTradingDays_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdTradingDays_lbl" xml:lang="en-US">Share Based Compensation Arrangement By Share-based Payment Award Threshold Trading Days</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdTradingDays_lbl" xml:lang="en-US">Share Based Compensation Arrangement By Share-based Payment Award Threshold Trading Days</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardThresholdTradingDays_lbl" xml:lang="en-US">Common stock trading days</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_AwardTypeAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AwardTypeAxis_lbl" xml:lang="en-US">Award Type [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" xml:lang="en-US">Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" xml:lang="en-US">Award Type [Domain]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="us-gaap_RestrictedStockMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockMember" xlink:to="us-gaap_RestrictedStockMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RestrictedStockMember_lbl" xml:lang="en-US">Restricted Stock [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RestrictedStockMember_lbl" xml:lang="en-US">Restricted Stock [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TotalStockholderReturnBasedAwardsMember" xlink:label="cli_TotalStockholderReturnBasedAwardsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TotalStockholderReturnBasedAwardsMember" xlink:to="cli_TotalStockholderReturnBasedAwardsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TotalStockholderReturnBasedAwardsMember_lbl" xml:lang="en-US">Total Stockholder Return Based Awards [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TotalStockholderReturnBasedAwardsMember_lbl" xml:lang="en-US">Total Stockholder Return Based Awards [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TotalStockholderReturnBasedAwardsMember_lbl" xml:lang="en-US">Total Stockholder Return Based Awards [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xml:lang="en-US">Shares, Outstanding, Beginning balance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xml:lang="en-US">Unvested restricted stock outstanding</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xml:lang="en-US">Shares, Granted</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xml:lang="en-US">Shares granted</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xml:lang="en-US">Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xml:lang="en-US">Total unrecognized compensation cost</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_lbl" xml:lang="en-US">Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_lbl" xml:lang="en-US">Total unrecognized compensation cost, period of recognition</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PercentageOfSharesVested" xlink:label="cli_PercentageOfSharesVested" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PercentageOfSharesVested" xlink:to="cli_PercentageOfSharesVested_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PercentageOfSharesVested_lbl" xml:lang="en-US">Percentage Of Shares Vested</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PercentageOfSharesVested_lbl" xml:lang="en-US">Percentage Of Shares Vested</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PercentageOfSharesVested_lbl" xml:lang="en-US">Percentage of shares vested</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformancePeriod" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformancePeriod" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformancePeriod" xlink:to="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformancePeriod_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformancePeriod_lbl" xml:lang="en-US">Share Based Compensation Arrangement By Share-based Payment Award Performance Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformancePeriod_lbl" xml:lang="en-US">Share Based Compensation Arrangement By Share-based Payment Award Performance Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformancePeriod_lbl" xml:lang="en-US">Performance period</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PercentageOfAward" xlink:label="cli_PercentageOfAward" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PercentageOfAward" xlink:to="cli_PercentageOfAward_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PercentageOfAward_lbl" xml:lang="en-US">Percentage Of Award</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PercentageOfAward_lbl" xml:lang="en-US">Percentage Of Award</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PercentageOfAward_lbl" xml:lang="en-US">Percent of the award</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RemainingPercentageOfAward" xlink:label="cli_RemainingPercentageOfAward" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RemainingPercentageOfAward" xlink:to="cli_RemainingPercentageOfAward_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RemainingPercentageOfAward_lbl" xml:lang="en-US">Remaining Percentage Of The Award</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RemainingPercentageOfAward_lbl" xml:lang="en-US">Remaining Percentage Of The Award</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RemainingPercentageOfAward_lbl" xml:lang="en-US">Remaining percent of the award</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TotalStockholderReturnPercent" xlink:label="cli_TotalStockholderReturnPercent" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TotalStockholderReturnPercent" xlink:to="cli_TotalStockholderReturnPercent_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TotalStockholderReturnPercent_lbl" xml:lang="en-US">Total Stockholder Return, Percent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TotalStockholderReturnPercent_lbl" xml:lang="en-US">Total Stockholder Return, Percent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TotalStockholderReturnPercent_lbl" xml:lang="en-US">TSR percent</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CommonStockDividendsPerSharePaidPercentPayableOnCommonUnit" xlink:label="cli_CommonStockDividendsPerSharePaidPercentPayableOnCommonUnit" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CommonStockDividendsPerSharePaidPercentPayableOnCommonUnit" xlink:to="cli_CommonStockDividendsPerSharePaidPercentPayableOnCommonUnit_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CommonStockDividendsPerSharePaidPercentPayableOnCommonUnit_lbl" xml:lang="en-US">Common Stock Dividends Per Share Paid Percent, Payable On Common Unit</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CommonStockDividendsPerSharePaidPercentPayableOnCommonUnit_lbl" xml:lang="en-US">Common Stock Dividends Per Share Paid Percent, Payable On Common Unit</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_CommonStockDividendsPerSharePaidPercentPayableOnCommonUnit_lbl" xml:lang="en-US">Dividends paid, percent representing common unit of limited partnership interest</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CommonStockDividendsPerSharePaidPercentPayableUponVestingOfLongTermInvestmentPlanUnit" xlink:label="cli_CommonStockDividendsPerSharePaidPercentPayableUponVestingOfLongTermInvestmentPlanUnit" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CommonStockDividendsPerSharePaidPercentPayableUponVestingOfLongTermInvestmentPlanUnit" xlink:to="cli_CommonStockDividendsPerSharePaidPercentPayableUponVestingOfLongTermInvestmentPlanUnit_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CommonStockDividendsPerSharePaidPercentPayableUponVestingOfLongTermInvestmentPlanUnit_lbl" xml:lang="en-US">Common Stock Dividends Per Share Paid Percent, Payable Upon Vesting Of Long-Term Investment Plan Unit</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CommonStockDividendsPerSharePaidPercentPayableUponVestingOfLongTermInvestmentPlanUnit_lbl" xml:lang="en-US">Common Stock Dividends Per Share Paid Percent, Payable Upon Vesting Of Long-Term Investment Plan Unit</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_CommonStockDividendsPerSharePaidPercentPayableUponVestingOfLongTermInvestmentPlanUnit_lbl" xml:lang="en-US">Dividends paid, percent payable upon vesting of LTIP Unit</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MaximumPercentageOfRetainerFeeDirectorsMayElectToDeferToStockUnits" xlink:label="cli_MaximumPercentageOfRetainerFeeDirectorsMayElectToDeferToStockUnits" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MaximumPercentageOfRetainerFeeDirectorsMayElectToDeferToStockUnits" xlink:to="cli_MaximumPercentageOfRetainerFeeDirectorsMayElectToDeferToStockUnits_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MaximumPercentageOfRetainerFeeDirectorsMayElectToDeferToStockUnits_lbl" xml:lang="en-US">Maximum Percentage Of Retainer Fee Directors May Elect To Defer To Stock Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MaximumPercentageOfRetainerFeeDirectorsMayElectToDeferToStockUnits_lbl" xml:lang="en-US">Maximum Percentage Of Retainer Fee Directors May Elect To Defer To Stock Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MaximumPercentageOfRetainerFeeDirectorsMayElectToDeferToStockUnits_lbl" xml:lang="en-US">Maximum percentage of retainer fee that directors may defer</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DeferredStockUnitsSharesEarned" xlink:label="cli_DeferredStockUnitsSharesEarned" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DeferredStockUnitsSharesEarned" xlink:to="cli_DeferredStockUnitsSharesEarned_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DeferredStockUnitsSharesEarned_lbl" xml:lang="en-US">Deferred stock units earned.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DeferredStockUnitsSharesEarned_lbl" xml:lang="en-US">Deferred Stock Units Shares Earned</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_DeferredStockUnitsSharesEarned_lbl" xml:lang="en-US">Deferred stock units earned</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DeferredStockUnitsOutstanding" xlink:label="cli_DeferredStockUnitsOutstanding" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DeferredStockUnitsOutstanding" xlink:to="cli_DeferredStockUnitsOutstanding_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DeferredStockUnitsOutstanding_lbl" xml:lang="en-US">Deferred stock units outstanding.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DeferredStockUnitsOutstanding_lbl" xml:lang="en-US">Deferred Stock Units Outstanding</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_DeferredStockUnitsOutstanding_lbl" xml:lang="en-US">Deferred stock units outstanding</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_UnvestedRestrictedStockMember" xlink:label="cli_UnvestedRestrictedStockMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_UnvestedRestrictedStockMember" xlink:to="cli_UnvestedRestrictedStockMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_UnvestedRestrictedStockMember_lbl" xml:lang="en-US">Unvested Restricted Stock [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_UnvestedRestrictedStockMember_lbl" xml:lang="en-US">Unvested Restricted Stock [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_UnvestedRestrictedStockMember_lbl" xml:lang="en-US">Unvested Restricted Stock [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xml:lang="en-US">Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xml:lang="en-US">Anti-dilutive securities excluded from the computation of earnings per share</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockDividendsPerShareDeclared" xlink:label="us-gaap_CommonStockDividendsPerShareDeclared" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockDividendsPerShareDeclared" xlink:to="us-gaap_CommonStockDividendsPerShareDeclared_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockDividendsPerShareDeclared_lbl" xml:lang="en-US">Dividends declared per common share</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable" xlink:to="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_lbl" xml:lang="en-US">Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_lbl" xml:lang="en-US">Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions_lbl" xml:lang="en-US">Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions_lbl" xml:lang="en-US">Shares Under Options - Outstanding, ending balance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions_lbl" xml:lang="en-US">Shares Under Options - Outstanding, beginning balance</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsForfeitedOrExpiredInPeriod" xlink:label="cli_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsForfeitedOrExpiredInPeriod" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsForfeitedOrExpiredInPeriod" xlink:to="cli_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsForfeitedOrExpiredInPeriod_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsForfeitedOrExpiredInPeriod_lbl" xml:lang="en-US">ShareBased Compensation Arrangement By ShareBased Payment Award Options Grants, Forfeited, Or Expired In Period</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsForfeitedOrExpiredInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US">ShareBased Compensation Arrangement By ShareBased Payment Award Options Grants, Forfeited, Or Expired In Period Weighted Average Exercise Price</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsForfeitedOrExpiredInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US">ShareBased Compensation Arrangement By ShareBased Payment Award Options Grants, Forfeited, Or Expired In Period Weighted Average Exercise Price</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsForfeitedOrExpiredInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US">Weighted Average Exercise Price - Granted, Lapsed or Cancelled</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US">Weighted Average Exercise Price - Lapsed or Cancelled</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_lbl" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_lbl" xml:lang="en-US">Aggregate Intrinsic Value, Outstanding, ending balance</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_lbl" xml:lang="en-US">Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_lbl" xml:lang="en-US">Outstanding stock option price range, lower range</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xml:lang="en-US">Shares, Forfeited</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US">Weighted-Average Grant-Date Fair Value, Outstanding ending balance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US">Weighted-Average Grant-Date Fair Value, Outstanding beginning balance</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US">Weighted-Average Grant-Date Fair Value, Granted</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US">Weighted-Average Grant-Date Fair Value, Vested</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US">Weighted-Average Grant-Date Fair Value, Forfeited</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NumberOfExecutiveOfficersThatWereGrantedRestrictedStockAwards" xlink:label="cli_NumberOfExecutiveOfficersThatWereGrantedRestrictedStockAwards" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NumberOfExecutiveOfficersThatWereGrantedRestrictedStockAwards" xlink:to="cli_NumberOfExecutiveOfficersThatWereGrantedRestrictedStockAwards_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfExecutiveOfficersThatWereGrantedRestrictedStockAwards_lbl" xml:lang="en-US">Number Of Executive Officers That Were Granted Restricted Stock Awards</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfExecutiveOfficersThatWereGrantedRestrictedStockAwards_lbl" xml:lang="en-US">Number Of Executive Officers That Were Granted Restricted Stock Awards</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfExecutiveOfficersThatWereGrantedRestrictedStockAwards_lbl" xml:lang="en-US">Number of executive officers that were granted restricted stock awards</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" xlink:to="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US">Income from continuing operations</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:label="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US">Net income (loss)</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemable" xlink:label="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemable" xlink:to="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemable_lbl" xml:lang="en-US">Noncontrolling Interest, Redemption Value Adjustment, Redeemable</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemable_lbl" xml:lang="en-US">Noncontrolling Interest, Redemption Value Adjustment, Redeemable</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemable_lbl" xml:lang="en-US">Deduct: Redeemable noncontrolling interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:label="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemable_lbl" xml:lang="en-US">Redeemable noncontrolling interest</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemableBeforeOperatingPartnership" xlink:label="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemableBeforeOperatingPartnership" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemableBeforeOperatingPartnership" xlink:to="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemableBeforeOperatingPartnership_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemableBeforeOperatingPartnership_lbl" xml:lang="en-US">Noncontrolling Interest, Redemption Value Adjustment, Redeemable Before Operating Partnership</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemableBeforeOperatingPartnership_lbl" xml:lang="en-US">Noncontrolling Interest, Redemption Value Adjustment, Redeemable Before Operating Partnership</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemableBeforeOperatingPartnership_lbl" xml:lang="en-US">Deduct: Redemption value adjustment of redeemable noncontrolling interests</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_lbl" xml:lang="en-US">Net Income (Loss) Available to Common Stockholders, Basic</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_lbl" xml:lang="en-US">Net income (loss) available to common shareholders for basic earnings per share</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemableInOperatingPartnership" xlink:label="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemableInOperatingPartnership" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemableInOperatingPartnership" xlink:to="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemableInOperatingPartnership_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemableInOperatingPartnership_lbl" xml:lang="en-US">Noncontrolling Interest Redemption Value Adjustment Redeemable In Operating Partnership</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemableInOperatingPartnership_lbl" xml:lang="en-US">Noncontrolling Interest Redemption Value Adjustment Redeemable In Operating Partnership</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_NoncontrollingInterestRedemptionValueAdjustmentRedeemableInOperatingPartnership_lbl" xml:lang="en-US">Deduct: Redemption value adjustment of redeemable noncontrolling interest in Operating Partnership</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_lbl" xml:lang="en-US">Net Income (Loss) Available to Common Stockholders, Diluted</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_lbl" xml:lang="en-US">Net income (loss) for diluted earnings per share</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CommonUnits" xlink:label="cli_CommonUnits" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CommonUnits_lbl" xml:lang="en-US">Common units.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CommonUnits_lbl" xml:lang="en-US">Common Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_CommonUnits_lbl" xml:lang="en-US">Add: Operating Partnership - common units</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RestrictedStockAwardsShares" xlink:label="cli_RestrictedStockAwardsShares" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RestrictedStockAwardsShares" xlink:to="cli_RestrictedStockAwardsShares_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RestrictedStockAwardsShares_lbl" xml:lang="en-US">Restricted Stock Awards, shares.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RestrictedStockAwardsShares_lbl" xml:lang="en-US">Restricted Stock Awards Shares</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_RestrictedStockAwardsShares_lbl" xml:lang="en-US">Restricted Stock Awards</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_StockOptions" xlink:label="cli_StockOptions" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_StockOptions_lbl" xml:lang="en-US">Stock Options</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_StockOptions_lbl" xml:lang="en-US">Stock Options</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_StockOptions_lbl" xml:lang="en-US">Stock Options</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FutureDevelopmentsMember" xlink:label="cli_FutureDevelopmentsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FutureDevelopmentsMember" xlink:to="cli_FutureDevelopmentsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FutureDevelopmentsMember_lbl" xml:lang="en-US">Future Developments [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FutureDevelopmentsMember_lbl" xml:lang="en-US">Future Developments [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FutureDevelopmentsMember_lbl" xml:lang="en-US">Future Developments [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NumberOfCommonSharesReceivedUponRedemptionOfCommonUnits_lbl" xml:lang="en-US">Number Of Common Shares Received Upon Redemption Of Common Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NumberOfCommonSharesReceivedUponRedemptionOfCommonUnits_lbl" xml:lang="en-US">Number Of Common Shares Received Upon Redemption Of Common Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NumberOfCommonSharesReceivedUponRedemptionOfCommonUnits_lbl" xml:lang="en-US">Number of common shares received upon redemption of common units</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RebalanceOfOwnershipPercentage" xlink:label="cli_RebalanceOfOwnershipPercentage" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RebalanceOfOwnershipPercentage_lbl" xml:lang="en-US">Rebalance Of Ownership Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RebalanceOfOwnershipPercentage_lbl" xml:lang="en-US">Rebalance Of Ownership Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_RebalanceOfOwnershipPercentage_lbl" xml:lang="en-US">Rebalance of ownership percentage</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners" xlink:label="us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_lbl" xml:lang="en-US">Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_lbl" xml:lang="en-US">Percentage of noncontrolling interest</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DistributionOfCashFlowToIndividualCompaniesPercentage" xlink:label="cli_DistributionOfCashFlowToIndividualCompaniesPercentage" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DistributionOfCashFlowToIndividualCompaniesPercentage_lbl" xml:lang="en-US">Distribution of cash flow to individual companies percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DistributionOfCashFlowToIndividualCompaniesPercentage_lbl" xml:lang="en-US">Distribution Of Cash Flow To Individual Companies Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DistributionOfCashFlowToIndividualCompaniesPercentage_lbl" xml:lang="en-US">Excess net cash flow remaining after the distribution to the Company</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonUnitIssued" xlink:to="us-gaap_CommonUnitIssued_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonUnitIssued_lbl" xml:lang="en-US">Common Unit, Issued</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonUnitIssued_lbl" xml:lang="en-US">Issuance of common units</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonUnitIssuanceValue" xlink:label="us-gaap_CommonUnitIssuanceValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonUnitIssuanceValue" xlink:to="us-gaap_CommonUnitIssuanceValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonUnitIssuanceValue_lbl" xml:lang="en-US">Common Unit, Issuance Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonUnitIssuanceValue_lbl" xml:lang="en-US">Common unit value</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CommonUnitsRedeemedForCommonShares" xlink:label="cli_CommonUnitsRedeemedForCommonShares" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CommonUnitsRedeemedForCommonShares" xlink:to="cli_CommonUnitsRedeemedForCommonShares_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CommonUnitsRedeemedForCommonShares_lbl" xml:lang="en-US">Common Units Redeemed For Common Shares</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CommonUnitsRedeemedForCommonShares_lbl" xml:lang="en-US">Common Units Redeemed For Common Shares</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_CommonUnitsRedeemedForCommonShares_lbl" xml:lang="en-US">Redemption of common units for shares of common stock</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CommonUnitsIssuanceOfUnits" xlink:label="cli_CommonUnitsIssuanceOfUnits" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CommonUnitsIssuanceOfUnits" xlink:to="cli_CommonUnitsIssuanceOfUnits_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CommonUnitsIssuanceOfUnits_lbl" xml:lang="en-US">Common Units, Issuance Of Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CommonUnitsIssuanceOfUnits_lbl" xml:lang="en-US">Common Units, Issuance Of Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_CommonUnitsIssuanceOfUnits_lbl" xml:lang="en-US">Issuance of units, Common Units</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LongTermIncentivePlanIssuanceOfUnits" xlink:label="cli_LongTermIncentivePlanIssuanceOfUnits" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LongTermIncentivePlanIssuanceOfUnits" xlink:to="cli_LongTermIncentivePlanIssuanceOfUnits_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LongTermIncentivePlanIssuanceOfUnits_lbl" xml:lang="en-US">Long Term Incentive Plan, Issuance of Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LongTermIncentivePlanIssuanceOfUnits_lbl" xml:lang="en-US">Long Term Incentive Plan, Issuance of Units</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_LongTermIncentivePlanIssuanceOfUnits_lbl" xml:lang="en-US">Issuance of units, LTIP Units</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LongTermIncentivePlanUnitsForfeited" xlink:label="cli_LongTermIncentivePlanUnitsForfeited" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LongTermIncentivePlanUnitsForfeited" xlink:to="cli_LongTermIncentivePlanUnitsForfeited_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LongTermIncentivePlanUnitsForfeited_lbl" xml:lang="en-US">Long Term Incentive Plan Units Forfeited</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LongTermIncentivePlanUnitsForfeited_lbl" xml:lang="en-US">Long Term Incentive Plan Units Forfeited</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:label="cli_LongTermIncentivePlanUnitsForfeited_lbl" xml:lang="en-US">Cancellation of units</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl" xml:lang="en-US">Schedule of Segment Reporting Information, by Segment [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementGeographicalAxis" xlink:label="us-gaap_StatementGeographicalAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementGeographicalAxis" xlink:to="us-gaap_StatementGeographicalAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementGeographicalAxis_lbl" xml:lang="en-US">Geographical [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentGeographicalDomain" xlink:label="us-gaap_SegmentGeographicalDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentGeographicalDomain" xlink:to="us-gaap_SegmentGeographicalDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentGeographicalDomain_lbl" xml:lang="en-US">Segment Geographical [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SegmentGeographicalDomain_lbl" xml:lang="en-US">Geographical [Domain]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ForeignCountryMember" xlink:label="us-gaap_ForeignCountryMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignCountryMember" xlink:to="us-gaap_ForeignCountryMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ForeignCountryMember_lbl" xml:lang="en-US">Foreign Country [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ForeignCountryMember_lbl" xml:lang="en-US">Foreign Locations [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NumberOfReportableSegments" xlink:label="us-gaap_NumberOfReportableSegments" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfReportableSegments" xlink:to="us-gaap_NumberOfReportableSegments_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NumberOfReportableSegments_lbl" xml:lang="en-US">Number of Reportable Segments</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NumberOfReportableSegments_lbl" xml:lang="en-US">Number of business segments</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Revenues" xlink:label="us-gaap_Revenues" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Revenues" xlink:to="us-gaap_Revenues_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Revenues_lbl" xml:lang="en-US">Revenues</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_Revenues_lbl" xml:lang="en-US">Revenue</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NoncurrentAssets" xlink:label="us-gaap_NoncurrentAssets" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncurrentAssets" xlink:to="us-gaap_NoncurrentAssets_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NoncurrentAssets_lbl" xml:lang="en-US">Long-Lived Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NoncurrentAssets_lbl" xml:lang="en-US">Long lived assets</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="us-gaap_StatementBusinessSegmentsAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementBusinessSegmentsAxis" xlink:to="us-gaap_StatementBusinessSegmentsAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementBusinessSegmentsAxis_lbl" xml:lang="en-US">Business Segments [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentDomain" xlink:label="us-gaap_SegmentDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentDomain" xlink:to="us-gaap_SegmentDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentDomain_lbl" xml:lang="en-US">Segment [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SegmentDomain_lbl" xml:lang="en-US">Segment [Domain]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RealEstateCommercialAndOtherSegmentMember" xlink:label="cli_RealEstateCommercialAndOtherSegmentMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RealEstateCommercialAndOtherSegmentMember" xlink:to="cli_RealEstateCommercialAndOtherSegmentMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RealEstateCommercialAndOtherSegmentMember_lbl" xml:lang="en-US">Real Estate Commercial And Other Segment [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RealEstateCommercialAndOtherSegmentMember_lbl" xml:lang="en-US">Real Estate Commercial And Other Segment [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RealEstateCommercialAndOtherSegmentMember_lbl" xml:lang="en-US">Commercial And Other Real Estate [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MultipleFamilyRealEstateAndServicesSegmentMember" xlink:label="cli_MultipleFamilyRealEstateAndServicesSegmentMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MultipleFamilyRealEstateAndServicesSegmentMember" xlink:to="cli_MultipleFamilyRealEstateAndServicesSegmentMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MultipleFamilyRealEstateAndServicesSegmentMember_lbl" xml:lang="en-US">Multiple-Family Real Estate And Services Segment [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MultipleFamilyRealEstateAndServicesSegmentMember_lbl" xml:lang="en-US">Multiple Family Real Estate And Services Segment [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MultipleFamilyRealEstateAndServicesSegmentMember_lbl" xml:lang="en-US">Multiple-Family Real Estate &amp; Services [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OperatingAndInterestExpenses" xlink:label="cli_OperatingAndInterestExpenses" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OperatingAndInterestExpenses" xlink:to="cli_OperatingAndInterestExpenses_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OperatingAndInterestExpenses_lbl" xml:lang="en-US">Total operating and interest expenses.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OperatingAndInterestExpenses_lbl" xml:lang="en-US">Operating And Interest Expenses</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_OperatingAndInterestExpenses_lbl" xml:lang="en-US">Total operating and interest expenses</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment" xlink:label="cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment" xlink:to="cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment_lbl" xml:lang="en-US">Segment Reporting Information, Net Operating Income (Loss) For Reportable Segment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment_lbl" xml:lang="en-US">Segment Reporting Information, Net Operating Income (Loss) For Reportable Segment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment_lbl" xml:lang="en-US">Net operating income (loss)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment_lbl" xml:lang="en-US">Net operating income</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LongLivedAssets" xlink:label="cli_LongLivedAssets" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LongLivedAssets" xlink:to="cli_LongLivedAssets_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LongLivedAssets_lbl" xml:lang="en-US">Long Lived Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LongLivedAssets_lbl" xml:lang="en-US">Long Lived Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_LongLivedAssets_lbl" xml:lang="en-US">Total long-lived assets</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_lbl" xml:lang="en-US">Schedule of Related Party Transactions, by Related Party [Table]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LeasedPropertyMember" xlink:label="cli_LeasedPropertyMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LeasedPropertyMember" xlink:to="cli_LeasedPropertyMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LeasedPropertyMember_lbl" xml:lang="en-US">Leased Property [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LeasedPropertyMember_lbl" xml:lang="en-US">Leased Property [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_LeasedPropertyMember_lbl" xml:lang="en-US">Leased Property [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_lbl" xml:lang="en-US">Related Party [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="us-gaap_RelatedPartyDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyDomain_lbl" xml:lang="en-US">Related Party [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RelatedPartyDomain_lbl" xml:lang="en-US">Related Party [Domain]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MackMember" xlink:label="cli_MackMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MackMember" xlink:to="cli_MackMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MackMember_lbl" xml:lang="en-US">Mack [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MackMember_lbl" xml:lang="en-US">Mack [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MackMember_lbl" xml:lang="en-US">Mack [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RGMember" xlink:label="cli_RGMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RGMember" xlink:to="cli_RGMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RGMember_lbl" xml:lang="en-US">RG [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RGMember_lbl" xml:lang="en-US">R G [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RGMember_lbl" xml:lang="en-US">RG [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="us-gaap_RelatedPartyTransactionLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionLineItems" xlink:to="us-gaap_RelatedPartyTransactionLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionLineItems_lbl" xml:lang="en-US">Related Party Transaction [Line Items]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OperatingLeasesExpirationDate" xlink:label="cli_OperatingLeasesExpirationDate" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OperatingLeasesExpirationDate" xlink:to="cli_OperatingLeasesExpirationDate_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OperatingLeasesExpirationDate_lbl" xml:lang="en-US">Operating Leases, Expiration Date</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OperatingLeasesExpirationDate_lbl" xml:lang="en-US">Operating Leases, Expiration Date</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OperatingLeasesExpirationDate_lbl" xml:lang="en-US">Lease expiration date</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OperatingLeasesNumberOfExtensionOptions" xlink:label="cli_OperatingLeasesNumberOfExtensionOptions" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OperatingLeasesNumberOfExtensionOptions" xlink:to="cli_OperatingLeasesNumberOfExtensionOptions_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OperatingLeasesNumberOfExtensionOptions_lbl" xml:lang="en-US">Operating Leases, Number Of Extension Options</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OperatingLeasesNumberOfExtensionOptions_lbl" xml:lang="en-US">Operating Leases, Number Of Extension Options</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OperatingLeasesNumberOfExtensionOptions_lbl" xml:lang="en-US">Number of lease options</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OperatingLeasesExtensionperiod" xlink:label="cli_OperatingLeasesExtensionperiod" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OperatingLeasesExtensionperiod" xlink:to="cli_OperatingLeasesExtensionperiod_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OperatingLeasesExtensionperiod_lbl" xml:lang="en-US">Operating Leases, ExtensionPeriod</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OperatingLeasesExtensionperiod_lbl" xml:lang="en-US">Operating Leases, ExtensionPeriod</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OperatingLeasesExtensionperiod_lbl" xml:lang="en-US">Lease extension period</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DueFromRelatedParties" xlink:label="us-gaap_DueFromRelatedParties" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DueFromRelatedParties" xlink:to="us-gaap_DueFromRelatedParties_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DueFromRelatedParties_lbl" xml:lang="en-US">Due from Related Parties</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DueFromRelatedParties_lbl" xml:lang="en-US">Due from related parties</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueFromRelatedParties" xlink:label="us-gaap_RevenueFromRelatedParties" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromRelatedParties" xlink:to="us-gaap_RevenueFromRelatedParties_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenueFromRelatedParties_lbl" xml:lang="en-US">Revenue from Related Parties</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RevenueFromRelatedParties_lbl" xml:lang="en-US">Related party revenue</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationByPropertyTable" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationByPropertyTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateAndAccumulatedDepreciationByPropertyTable" xlink:to="us-gaap_RealEstateAndAccumulatedDepreciationByPropertyTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationByPropertyTable_lbl" xml:lang="en-US">SEC Schedule III, Real Estate and Accumulated Depreciation, by Property [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationLineItems" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateAndAccumulatedDepreciationLineItems" xlink:to="us-gaap_RealEstateAndAccumulatedDepreciationLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationLineItems_lbl" xml:lang="en-US">SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RealEstateAndAccumulatedDepreciationDateConstructed" xlink:label="cli_RealEstateAndAccumulatedDepreciationDateConstructed" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RealEstateAndAccumulatedDepreciationDateConstructed" xlink:to="cli_RealEstateAndAccumulatedDepreciationDateConstructed_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RealEstateAndAccumulatedDepreciationDateConstructed_lbl" xml:lang="en-US">Real Estate And Accumulated Depreciation, Date Constructed</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RealEstateAndAccumulatedDepreciationDateConstructed_lbl" xml:lang="en-US">Real Estate And Accumulated Depreciation, Date Constructed</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RealEstateAndAccumulatedDepreciationDateConstructed_lbl" xml:lang="en-US">Year Built</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RealEstateAndAccumulatedDepreciationDateOfAcquisition" xlink:label="cli_RealEstateAndAccumulatedDepreciationDateOfAcquisition" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RealEstateAndAccumulatedDepreciationDateOfAcquisition" xlink:to="cli_RealEstateAndAccumulatedDepreciationDateOfAcquisition_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RealEstateAndAccumulatedDepreciationDateOfAcquisition_lbl" xml:lang="en-US">Real Estate And Accumulated Depreciation, Date Of Acquisition</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RealEstateAndAccumulatedDepreciationDateOfAcquisition_lbl" xml:lang="en-US">Real Estate And Accumulated Depreciation, Date Of Acquisition</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RealEstateAndAccumulatedDepreciationDateOfAcquisition_lbl" xml:lang="en-US">Acquired</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances" xlink:to="us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances_lbl" xml:lang="en-US">Real Estate and Accumulated Depreciation, Amount of Encumbrances</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances_lbl" xml:lang="en-US">Related Encumbrances</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand" xlink:to="us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand_lbl" xml:lang="en-US">Real Estate and Accumulated Depreciation, Initial Cost of Land</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand_lbl" xml:lang="en-US">Initial Costs, Land</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements" xlink:to="us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements_lbl" xml:lang="en-US">Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements_lbl" xml:lang="en-US">Initial Costs, Building and Improvements</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts" xlink:to="us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts_lbl" xml:lang="en-US">Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts_lbl" xml:lang="en-US">Costs Capitalized Subsequent to Acquisition</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand" xlink:to="us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand_lbl" xml:lang="en-US">Real Estate and Accumulated Depreciation, Carrying Amount of Land</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand_lbl" xml:lang="en-US">Gross Amount at Which Carried at Close of Period, Land</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements" xlink:to="us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements_lbl" xml:lang="en-US">Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements_lbl" xml:lang="en-US">Gross Amount at Which Carried at Close of Period, Building and Improvements</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateGrossAtCarryingValue" xlink:label="us-gaap_RealEstateGrossAtCarryingValue" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateGrossAtCarryingValue" xlink:to="us-gaap_RealEstateGrossAtCarryingValue_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateGrossAtCarryingValue_lbl" xml:lang="en-US">Real Estate, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_RealEstateGrossAtCarryingValue_lbl" xml:lang="en-US">Rental Properties, Balance at end of year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_RealEstateGrossAtCarryingValue_lbl" xml:lang="en-US">Rental Properties, Balance at beginning of year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_RealEstateGrossAtCarryingValue_lbl" xml:lang="en-US">Total</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAccumulatedDepreciation" xlink:label="us-gaap_RealEstateAccumulatedDepreciation" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateAccumulatedDepreciation" xlink:to="us-gaap_RealEstateAccumulatedDepreciation_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateAccumulatedDepreciation_lbl" xml:lang="en-US">Real Estate Accumulated Depreciation</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_RealEstateAccumulatedDepreciation_lbl" xml:lang="en-US">Accumulated Depreciation, Balance at end of year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_RealEstateAccumulatedDepreciation_lbl" xml:lang="en-US">Accumulated Depreciation, Balance at beginning of year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_RealEstateAccumulatedDepreciation_lbl" xml:lang="en-US">Accumulated Depreciation</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RealEstateAggregateCostTaxPurpose" xlink:label="cli_RealEstateAggregateCostTaxPurpose" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RealEstateAggregateCostTaxPurpose" xlink:to="cli_RealEstateAggregateCostTaxPurpose_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RealEstateAggregateCostTaxPurpose_lbl" xml:lang="en-US">Real Estate Aggregate Cost, Tax Purpose</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RealEstateAggregateCostTaxPurpose_lbl" xml:lang="en-US">Real Estate Aggregate Cost, Tax Purpose</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationLifeUsedForDepreciation1" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationLifeUsedForDepreciation1" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateAndAccumulatedDepreciationLifeUsedForDepreciation1" xlink:to="us-gaap_RealEstateAndAccumulatedDepreciationLifeUsedForDepreciation1_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationLifeUsedForDepreciation1_lbl" xml:lang="en-US">SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RealEstateAndAccumulatedDepreciationLifeUsedForDepreciation1_lbl" xml:lang="en-US">Useful Live</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateOtherAdditions" xlink:label="us-gaap_RealEstateOtherAdditions" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateOtherAdditions" xlink:to="us-gaap_RealEstateOtherAdditions_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateOtherAdditions_lbl" xml:lang="en-US">Real Estate, Other Additions</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RealEstateOtherAdditions_lbl" xml:lang="en-US">Rental Properties, Additions</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RealEstateCostOfRealEstateHeldForSale" xlink:label="cli_RealEstateCostOfRealEstateHeldForSale" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RealEstateCostOfRealEstateHeldForSale" xlink:to="cli_RealEstateCostOfRealEstateHeldForSale_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RealEstateCostOfRealEstateHeldForSale_lbl" xml:lang="en-US">Real Estate Cost Of Real Estate Held For Sale</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RealEstateCostOfRealEstateHeldForSale_lbl" xml:lang="en-US">Real Estate Cost Of Real Estate Held For Sale</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_RealEstateCostOfRealEstateHeldForSale_lbl" xml:lang="en-US">Rental Properties, Rental property held for sale</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateCostOfRealEstateSold" xlink:label="us-gaap_RealEstateCostOfRealEstateSold" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateCostOfRealEstateSold" xlink:to="us-gaap_RealEstateCostOfRealEstateSold_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateCostOfRealEstateSold_lbl" xml:lang="en-US">Real Estate, Cost of Real Estate Sold</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_RealEstateCostOfRealEstateSold_lbl" xml:lang="en-US">Rental Properties, Properties sold</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateOtherDeductions" xlink:label="us-gaap_RealEstateOtherDeductions" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateOtherDeductions" xlink:to="us-gaap_RealEstateOtherDeductions_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateOtherDeductions_lbl" xml:lang="en-US">Real Estate, Other Deductions</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RealEstateRetirementsOrDisposals_lbl" xml:lang="en-US">Real Estate, Retirements Or Disposals</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RealEstateRetirementsOrDisposals_lbl" xml:lang="en-US">Real Estate, Retirements Or Disposals</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_RealEstateRetirementsOrDisposals_lbl" xml:lang="en-US">Rental Properties, Retirements/disposals</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SECScheduleIIIRealEstateAccumulatedDepreciationDepreciationExpense" xlink:to="us-gaap_SECScheduleIIIRealEstateAccumulatedDepreciationDepreciationExpense_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SECScheduleIIIRealEstateAccumulatedDepreciationDepreciationExpense_lbl" xml:lang="en-US">Real Estate Accumulated Depreciation, Depreciation Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SECScheduleIIIRealEstateAccumulatedDepreciationDepreciationExpense_lbl" xml:lang="en-US">Accumulated Depreciation, Depreciation expense</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RealEstateAccumulatedDepreciationRealEstateHeldForSale" xlink:label="cli_RealEstateAccumulatedDepreciationRealEstateHeldForSale" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RealEstateAccumulatedDepreciationRealEstateHeldForSale" xlink:to="cli_RealEstateAccumulatedDepreciationRealEstateHeldForSale_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RealEstateAccumulatedDepreciationRealEstateHeldForSale_lbl" xml:lang="en-US">Real Estate Accumulated Depreciation Real Estate Held For Sale</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RealEstateAccumulatedDepreciationRealEstateHeldForSale_lbl" xml:lang="en-US">Real Estate Accumulated Depreciation Real Estate Held For Sale</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_RealEstateAccumulatedDepreciationRealEstateHeldForSale_lbl" xml:lang="en-US">Accumulated Depreciation, Rental property held for sale</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAccumulatedDepreciationRealEstateSold" xlink:label="us-gaap_RealEstateAccumulatedDepreciationRealEstateSold" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateAccumulatedDepreciationRealEstateSold" xlink:to="us-gaap_RealEstateAccumulatedDepreciationRealEstateSold_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RealEstateAccumulatedDepreciationRealEstateSold_lbl" xml:lang="en-US">Real Estate Accumulated Depreciation, Real Estate Sold</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_RealEstateAccumulatedDepreciationRealEstateSold_lbl" xml:lang="en-US">Accumulated Depreciation, Properties sold</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RealEstateAndAccumulatedDepreciationRepurposedBuildings" xlink:label="cli_RealEstateAndAccumulatedDepreciationRepurposedBuildings" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RealEstateAndAccumulatedDepreciationRepurposedBuildings" xlink:to="cli_RealEstateAndAccumulatedDepreciationRepurposedBuildings_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RealEstateAndAccumulatedDepreciationRepurposedBuildings_lbl" xml:lang="en-US">Real Estate and Accumulated Depreciation, Repurposed Buildings</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RealEstateAndAccumulatedDepreciationRepurposedBuildings_lbl" xml:lang="en-US">Real Estate and Accumulated Depreciation, Repurposed Buildings</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_RealEstateAndAccumulatedDepreciationRepurposedBuildings_lbl" xml:lang="en-US">Accumulated Depreciation, Repurposed buildings</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RealEstateAccumulatedDepreciationIncreaseDecreaseImpairmentCharges" xlink:label="cli_RealEstateAccumulatedDepreciationIncreaseDecreaseImpairmentCharges" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RealEstateAccumulatedDepreciationIncreaseDecreaseImpairmentCharges" xlink:to="cli_RealEstateAccumulatedDepreciationIncreaseDecreaseImpairmentCharges_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RealEstateAccumulatedDepreciationIncreaseDecreaseImpairmentCharges_lbl" xml:lang="en-US">Real Estate Accumulated Depreciation, Increase (Decrease) Impairment Charges</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RealEstateAccumulatedDepreciationIncreaseDecreaseImpairmentCharges_lbl" xml:lang="en-US">Real Estate Accumulated Depreciation, Increase (Decrease) Impairment Charges</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_RealEstateAccumulatedDepreciationIncreaseDecreaseImpairmentCharges_lbl" xml:lang="en-US">Accumulated Depreciation, Impairments</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RealEstateAccumulatedDepreciationRetirementsOrDisposals" xlink:label="cli_RealEstateAccumulatedDepreciationRetirementsOrDisposals" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RealEstateAccumulatedDepreciationRetirementsOrDisposals" xlink:to="cli_RealEstateAccumulatedDepreciationRetirementsOrDisposals_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RealEstateAccumulatedDepreciationRetirementsOrDisposals_lbl" xml:lang="en-US">Real Estate Accumulated Depreciation, Retirements Or Disposals</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RealEstateAccumulatedDepreciationRetirementsOrDisposals_lbl" xml:lang="en-US">Real Estate Accumulated Depreciation, Retirements Or Disposals</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="cli_RealEstateAccumulatedDepreciationRetirementsOrDisposals_lbl" xml:lang="en-US">Accumulated Depreciation, Retirements/disposals</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgageLoansOnRealEstateScheduleTable" xlink:label="us-gaap_MortgageLoansOnRealEstateScheduleTable" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MortgageLoansOnRealEstateScheduleTable" xlink:to="us-gaap_MortgageLoansOnRealEstateScheduleTable_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageLoansOnRealEstateScheduleTable_lbl" xml:lang="en-US">Mortgage Loans on Real Estate Schedule [Table]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgageLoansOnRealEstateLineItems" xlink:label="us-gaap_MortgageLoansOnRealEstateLineItems" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MortgageLoansOnRealEstateLineItems" xlink:to="us-gaap_MortgageLoansOnRealEstateLineItems_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageLoansOnRealEstateLineItems_lbl" xml:lang="en-US">Mortgage Loans on Real Estate [Line Items]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MortgageLoansOnRealEstateInterestAccrualRate" xlink:label="cli_MortgageLoansOnRealEstateInterestAccrualRate" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MortgageLoansOnRealEstateInterestAccrualRate" xlink:to="cli_MortgageLoansOnRealEstateInterestAccrualRate_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MortgageLoansOnRealEstateInterestAccrualRate_lbl" xml:lang="en-US">Mortgage Loans on Real Estate, Interest Accrual Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MortgageLoansOnRealEstateInterestAccrualRate_lbl" xml:lang="en-US">Mortgage Loans on Real Estate, Interest Accrual Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MortgageLoansOnRealEstateInterestAccrualRate_lbl" xml:lang="en-US">Interest Accrual Rate</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgageLoansOnRealEstateInterestRate" xlink:label="us-gaap_MortgageLoansOnRealEstateInterestRate" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MortgageLoansOnRealEstateInterestRate" xlink:to="us-gaap_MortgageLoansOnRealEstateInterestRate_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageLoansOnRealEstateInterestRate_lbl" xml:lang="en-US">Mortgage Loans on Real Estate, Interest Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_MortgageLoansOnRealEstateInterestRate_lbl" xml:lang="en-US">Interest Payment Rate</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgageLoanOnRealEstateFinalMaturityDate" xlink:label="us-gaap_MortgageLoanOnRealEstateFinalMaturityDate" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MortgageLoanOnRealEstateFinalMaturityDate" xlink:to="us-gaap_MortgageLoanOnRealEstateFinalMaturityDate_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageLoanOnRealEstateFinalMaturityDate_lbl" xml:lang="en-US">Mortgage Loans on Real Estate, Final Maturity Date</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_MortgageLoanOnRealEstateFinalMaturityDate_lbl" xml:lang="en-US">Final Maturity Date</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgageLoansOnRealEstatePeriodicPaymentTerms" xlink:label="us-gaap_MortgageLoansOnRealEstatePeriodicPaymentTerms" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MortgageLoansOnRealEstatePeriodicPaymentTerms" xlink:to="us-gaap_MortgageLoansOnRealEstatePeriodicPaymentTerms_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageLoansOnRealEstatePeriodicPaymentTerms_lbl" xml:lang="en-US">Mortgage Loans on Real Estate, Periodic Payment Terms</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MortgageLoansOnRealEstatePeriodicPaymentTerms_lbl" xml:lang="en-US">Periodic Payment Terms</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgageLoansOnRealEstate" xlink:label="us-gaap_MortgageLoansOnRealEstate" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MortgageLoansOnRealEstate" xlink:to="us-gaap_MortgageLoansOnRealEstate_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageLoansOnRealEstate_lbl" xml:lang="en-US">Mortgage Loans on Real Estate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_MortgageLoansOnRealEstate_lbl" xml:lang="en-US">Ending Balance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_MortgageLoansOnRealEstate_lbl" xml:lang="en-US">Beginning Balance</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MortgageLoansOnRealEstateAccruedInterest" xlink:label="cli_MortgageLoansOnRealEstateAccruedInterest" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MortgageLoansOnRealEstateAccruedInterest" xlink:to="cli_MortgageLoansOnRealEstateAccruedInterest_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MortgageLoansOnRealEstateAccruedInterest_lbl" xml:lang="en-US">Mortgage Loans On Real Estate, Accrued Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MortgageLoansOnRealEstateAccruedInterest_lbl" xml:lang="en-US">Mortgage Loans On Real Estate, Accrued Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MortgageLoansOnRealEstateAccruedInterest_lbl" xml:lang="en-US">Accrued interest</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_LegalEntityAxis" xlink:label="dei_LegalEntityAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LegalEntityAxis" xlink:to="dei_LegalEntityAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_LegalEntityAxis_lbl" xml:lang="en-US">Legal Entity [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="dei_EntityDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityDomain" xlink:to="dei_EntityDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityDomain_lbl" xml:lang="en-US">Entity [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="dei_EntityDomain_lbl" xml:lang="en-US">Entity [Domain]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MackCaliRealtyLpMember" xlink:label="cli_MackCaliRealtyLpMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MackCaliRealtyLpMember" xlink:to="cli_MackCaliRealtyLpMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MackCaliRealtyLpMember_lbl" xml:lang="en-US">Mack Cali Realty LP [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MackCaliRealtyLpMember_lbl" xml:lang="en-US">Mack Cali Realty Lp [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MackCaliRealtyLpMember_lbl" xml:lang="en-US">Mack-Cali Realty LP [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PartnerCapitalComponentsAxis" xlink:label="us-gaap_PartnerCapitalComponentsAxis" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PartnerCapitalComponentsDomain_lbl" xml:lang="en-US">Partner Capital Components [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PartnerCapitalComponentsDomain_lbl" xml:lang="en-US">Partner Capital Components [Domain]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GeneralPartnerMember" xlink:label="us-gaap_GeneralPartnerMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GeneralPartnerMember_lbl" xml:lang="en-US">General Partner [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_GeneralPartnerMember_lbl" xml:lang="en-US">General Partner Common Units [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LimitedPartnerMember" xlink:label="us-gaap_LimitedPartnerMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LimitedPartnerMember" xlink:to="us-gaap_LimitedPartnerMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LimitedPartnerMember_lbl" xml:lang="en-US">Limited Partner [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LimitedPartnerMember_lbl" xml:lang="en-US">Limited Partner Common Units [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_GeneralPartnerCommonUnitholdersMember" xlink:label="cli_GeneralPartnerCommonUnitholdersMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_GeneralPartnerCommonUnitholdersMember_lbl" xml:lang="en-US">General Partner Common Unitholders [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_GeneralPartnerCommonUnitholdersMember_lbl" xml:lang="en-US">General Partner Common Unitholders [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RockpointGroupL.l.c.Member_lbl" xml:lang="en-US">Rockpoint Group, L.L.C. [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PruRoseRiverwalkGLLCMember_lbl" xml:lang="en-US">PruRose Riverwalk G, L.L.C. [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PruRosePortImperialSouthFifteenLlcAndPruRosePortImperialSouthThirteenLlcMember_lbl" xml:lang="en-US">Pru Rose Port Imperial South 15 L.L.C. And Pru Rose Port Imperial South 13 L.L.C. [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_KpgP100ImwJvLlcKeystonePennAndKeystoneTristateMember_lbl" xml:lang="en-US">KPG-P 100 IMW JV, LLC, Keystone-Penn And Keystone-Tristate [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ElmajoUrbanRenewalAssociatesLLCAndEstuaryUrbanRenewalAssociatesLLCMember_lbl" xml:lang="en-US">Elmajo Urban Renewal Associates, LLC And Estuary Urban Renewal Associates, LLC [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ElmajoUrbanRenewalAssociatesLLCAndEstuaryUrbanRenewalAssociatesLLCMember_lbl" xml:lang="en-US">Elmajo Urban Renewal Associates L L C And Estuary Urban Renewal Associates L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ElmajoUrbanRenewalAssociatesLLCAndEstuaryUrbanRenewalAssociatesLLCMember_lbl" xml:lang="en-US">Elmajo Urban Renewal Associates, LLC And Estuary Urban Renewal Associates, LLC [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_KpgMcgCurtisJvLLCMember" xlink:label="cli_KpgMcgCurtisJvLLCMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_KpgMcgCurtisJvLLCMember_lbl" xml:lang="en-US">KPG-MCG Curtis JV, LLC [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_KpgMcgCurtisJvLLCMember_lbl" xml:lang="en-US">Kpg Mcg Curtis Jv L L C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_KpgMcgCurtisJvLLCMember_lbl" xml:lang="en-US">KPG-MCG Curtis JV, LLC [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RedBankPortfolioMember" xlink:label="cli_RedBankPortfolioMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RedBankPortfolioMember" xlink:to="cli_RedBankPortfolioMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RedBankPortfolioMember_lbl" xml:lang="en-US">Red Bank Portfolio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RedBankPortfolioMember_lbl" xml:lang="en-US">Red Bank Portfolio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RedBankPortfolioMember_lbl" xml:lang="en-US">Red Bank Portfolio [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ShortHillsMadisonPortfolioMember" xlink:label="cli_ShortHillsMadisonPortfolioMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ShortHillsMadisonPortfolioMember" xlink:to="cli_ShortHillsMadisonPortfolioMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ShortHillsMadisonPortfolioMember_lbl" xml:lang="en-US">Short Hills / Madison Portfolio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ShortHillsMadisonPortfolioMember_lbl" xml:lang="en-US">Short Hills Madison Portfolio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ShortHillsMadisonPortfolioMember_lbl" xml:lang="en-US">Short Hills / Madison Portfolio [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AboveMarketInPlaceAndBelowMarketLeasesMember" xlink:label="cli_AboveMarketInPlaceAndBelowMarketLeasesMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AboveMarketInPlaceAndBelowMarketLeasesMember" xlink:to="cli_AboveMarketInPlaceAndBelowMarketLeasesMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AboveMarketInPlaceAndBelowMarketLeasesMember_lbl" xml:lang="en-US">Above Market, In-Place And Below Market Leases [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AboveMarketInPlaceAndBelowMarketLeasesMember_lbl" xml:lang="en-US">Above Market In Place And Below Market Leases [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AboveMarketInPlaceAndBelowMarketLeasesMember_lbl" xml:lang="en-US">Above Market, In-Place And Below Market Leases [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConstructionLoansMember" xlink:label="us-gaap_ConstructionLoansMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConstructionLoansMember" xlink:to="us-gaap_ConstructionLoansMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConstructionLoansMember_lbl" xml:lang="en-US">Construction Loans [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConstructionLoansMember_lbl" xml:lang="en-US">Construction Loan [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_QuarryPlaceAtTuckahoeMember" xlink:label="cli_QuarryPlaceAtTuckahoeMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_QuarryPlaceAtTuckahoeMember" xlink:to="cli_QuarryPlaceAtTuckahoeMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_QuarryPlaceAtTuckahoeMember_lbl" xml:lang="en-US">Quarry Place At Tuckahoe [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_QuarryPlaceAtTuckahoeMember_lbl" xml:lang="en-US">Quarry Place At Tuckahoe [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_QuarryPlaceAtTuckahoeMember_lbl" xml:lang="en-US">Quarry Place At Tuckahoe [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ChaseTwoAtOverlookRidgeMember" xlink:label="cli_ChaseTwoAtOverlookRidgeMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ChaseTwoAtOverlookRidgeMember" xlink:to="cli_ChaseTwoAtOverlookRidgeMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ChaseTwoAtOverlookRidgeMember_lbl" xml:lang="en-US">Chase Two At Overlook Ridge [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ChaseTwoAtOverlookRidgeMember_lbl" xml:lang="en-US">Chase Two At Overlook Ridge [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ChaseTwoAtOverlookRidgeMember_lbl" xml:lang="en-US">The Chase II At Overlook Ridge [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_QuarryPlaceAtTuckahoeAndChaseAtOverlookRidgeMember" xlink:label="cli_QuarryPlaceAtTuckahoeAndChaseAtOverlookRidgeMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_QuarryPlaceAtTuckahoeAndChaseAtOverlookRidgeMember" xlink:to="cli_QuarryPlaceAtTuckahoeAndChaseAtOverlookRidgeMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_QuarryPlaceAtTuckahoeAndChaseAtOverlookRidgeMember_lbl" xml:lang="en-US">Quarry Place At Tuckahoe And The Chase At Overlook Ridge [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_QuarryPlaceAtTuckahoeAndChaseAtOverlookRidgeMember_lbl" xml:lang="en-US">Quarry Place At Tuckahoe And Chase At Overlook Ridge [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_QuarryPlaceAtTuckahoeAndChaseAtOverlookRidgeMember_lbl" xml:lang="en-US">Quarry Place At Tuckahoe And The Chase II At Overlook Ridge [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MonacoNorthMember" xlink:label="cli_MonacoNorthMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MonacoNorthMember" xlink:to="cli_MonacoNorthMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MonacoNorthMember_lbl" xml:lang="en-US">Monaco North [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MonacoNorthMember_lbl" xml:lang="en-US">Monaco North [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MonacoNorthMember_lbl" xml:lang="en-US">Monaco North [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MonacoSouthMember" xlink:label="cli_MonacoSouthMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MonacoSouthMember" xlink:to="cli_MonacoSouthMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MonacoSouthMember_lbl" xml:lang="en-US">Monaco South [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MonacoSouthMember_lbl" xml:lang="en-US">Monaco South [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MonacoSouthMember_lbl" xml:lang="en-US">Monaco South [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_LeasesAcquiredInPlaceAndBelowMarketMember" xlink:label="cli_LeasesAcquiredInPlaceAndBelowMarketMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_LeasesAcquiredInPlaceAndBelowMarketMember" xlink:to="cli_LeasesAcquiredInPlaceAndBelowMarketMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_LeasesAcquiredInPlaceAndBelowMarketMember_lbl" xml:lang="en-US">Leases, Acquired-In-Place And Below Market [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_LeasesAcquiredInPlaceAndBelowMarketMember_lbl" xml:lang="en-US">Leases Acquired In Place And Below Market [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_LeasesAcquiredInPlaceAndBelowMarketMember_lbl" xml:lang="en-US">In-Place And Below Market Leases [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CranfordPortfolioMember" xlink:label="cli_CranfordPortfolioMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CranfordPortfolioMember" xlink:to="cli_CranfordPortfolioMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CranfordPortfolioMember_lbl" xml:lang="en-US">Cranford Portfolio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CranfordPortfolioMember_lbl" xml:lang="en-US">Cranford Portfolio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_CranfordPortfolioMember_lbl" xml:lang="en-US">Cranford Portfolio [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FourHundredFortyRouteTwentyTwoEastMember" xlink:label="cli_FourHundredFortyRouteTwentyTwoEastMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FourHundredFortyRouteTwentyTwoEastMember" xlink:to="cli_FourHundredFortyRouteTwentyTwoEastMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FourHundredFortyRouteTwentyTwoEastMember_lbl" xml:lang="en-US">Four Hundred Forty Route Twenty Two East [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FourHundredFortyRouteTwentyTwoEastMember_lbl" xml:lang="en-US">Four Hundred Forty Route Twenty Two East [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FourHundredFortyRouteTwentyTwoEastMember_lbl" xml:lang="en-US">440 Route 22 East [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeIndependenceWayMember" xlink:label="cli_ThreeIndependenceWayMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeIndependenceWayMember" xlink:to="cli_ThreeIndependenceWayMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeIndependenceWayMember_lbl" xml:lang="en-US">Three Independence Way [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeIndependenceWayMember_lbl" xml:lang="en-US">Three Independence Way [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeIndependenceWayMember_lbl" xml:lang="en-US">3 Independence Way [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredThreeCarnegieCenterMember" xlink:label="cli_OneHundredThreeCarnegieCenterMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredThreeCarnegieCenterMember" xlink:to="cli_OneHundredThreeCarnegieCenterMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredThreeCarnegieCenterMember_lbl" xml:lang="en-US">103 Carnegie Center [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredThreeCarnegieCenterMember_lbl" xml:lang="en-US">One Hundred Three Carnegie Center [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredThreeCarnegieCenterMember_lbl" xml:lang="en-US">103 Carnegie Center [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FourHundredChestnutRidgeRoadMember" xlink:label="cli_FourHundredChestnutRidgeRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FourHundredChestnutRidgeRoadMember" xlink:to="cli_FourHundredChestnutRidgeRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FourHundredChestnutRidgeRoadMember_lbl" xml:lang="en-US">Four Hundred Chestnut Ridge Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FourHundredChestnutRidgeRoadMember_lbl" xml:lang="en-US">Four Hundred Chestnut Ridge Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FourHundredChestnutRidgeRoadMember_lbl" xml:lang="en-US">400 Chestnut Ridge Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredFortyEastRidgewoodAvenueMember" xlink:label="cli_OneHundredFortyEastRidgewoodAvenueMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredFortyEastRidgewoodAvenueMember" xlink:to="cli_OneHundredFortyEastRidgewoodAvenueMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredFortyEastRidgewoodAvenueMember_lbl" xml:lang="en-US">One Hundred Forty East Ridgewood Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredFortyEastRidgewoodAvenueMember_lbl" xml:lang="en-US">One Hundred Forty East Ridgewood Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredFortyEastRidgewoodAvenueMember_lbl" xml:lang="en-US">140 East Ridgewood Avenue [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_BergenPortfolioMember" xlink:label="cli_BergenPortfolioMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_BergenPortfolioMember" xlink:to="cli_BergenPortfolioMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_BergenPortfolioMember_lbl" xml:lang="en-US">Bergen Portfolio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_BergenPortfolioMember_lbl" xml:lang="en-US">Bergen Portfolio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_BergenPortfolioMember_lbl" xml:lang="en-US">Bergen Portfolio [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeHundredSeventySevenSummerhillRoadMember" xlink:label="cli_ThreeHundredSeventySevenSummerhillRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeHundredSeventySevenSummerhillRoadMember" xlink:to="cli_ThreeHundredSeventySevenSummerhillRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeHundredSeventySevenSummerhillRoadMember_lbl" xml:lang="en-US">Three Hundred Seventy Seven Summerhill Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeHundredSeventySevenSummerhillRoadMember_lbl" xml:lang="en-US">Three Hundred Seventy Seven Summerhill Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeHundredSeventySevenSummerhillRoadMember_lbl" xml:lang="en-US">377 Summerhill Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SevenHundredExecutiveBoulevardMember" xlink:label="cli_SevenHundredExecutiveBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SevenHundredExecutiveBoulevardMember" xlink:to="cli_SevenHundredExecutiveBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SevenHundredExecutiveBoulevardMember_lbl" xml:lang="en-US">Seven Hundred Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SevenHundredExecutiveBoulevardMember_lbl" xml:lang="en-US">Seven Hundred Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SevenHundredExecutiveBoulevardMember_lbl" xml:lang="en-US">700 Executive Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TotowaPortfolioMember" xlink:label="cli_TotowaPortfolioMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TotowaPortfolioMember" xlink:to="cli_TotowaPortfolioMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TotowaPortfolioMember_lbl" xml:lang="en-US">Totowa Portfolio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TotowaPortfolioMember_lbl" xml:lang="en-US">Totowa Portfolio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TotowaPortfolioMember_lbl" xml:lang="en-US">Totowa Portfolio [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EightHundredNinetyMountainRoadMember" xlink:label="cli_EightHundredNinetyMountainRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EightHundredNinetyMountainRoadMember" xlink:to="cli_EightHundredNinetyMountainRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EightHundredNinetyMountainRoadMember_lbl" xml:lang="en-US">Eight Hundred Ninety Mountain Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EightHundredNinetyMountainRoadMember_lbl" xml:lang="en-US">Eight Hundred Ninety Mountain Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_EightHundredNinetyMountainRoadMember_lbl" xml:lang="en-US">890 Mountain Avenue [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredThirtyFiveChestnutRidgeRoadMember" xlink:label="cli_OneHundredThirtyFiveChestnutRidgeRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredThirtyFiveChestnutRidgeRoadMember" xlink:to="cli_OneHundredThirtyFiveChestnutRidgeRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredThirtyFiveChestnutRidgeRoadMember_lbl" xml:lang="en-US">One Hundred Thirty Five Chestnut Ridge Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredThirtyFiveChestnutRidgeRoadMember_lbl" xml:lang="en-US">One Hundred Thirty Five Chestnut Ridge Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredThirtyFiveChestnutRidgeRoadMember_lbl" xml:lang="en-US">135 Chestnut Ridge Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MoorestownPortfolioMember" xlink:label="cli_MoorestownPortfolioMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_MoorestownPortfolioMember" xlink:to="cli_MoorestownPortfolioMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MoorestownPortfolioMember_lbl" xml:lang="en-US">Moorestown Portfolio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MoorestownPortfolioMember_lbl" xml:lang="en-US">Moorestown Portfolio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MoorestownPortfolioMember_lbl" xml:lang="en-US">Moorestown Portfolio [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneEnterpriseBoulevardMember" xlink:label="cli_OneEnterpriseBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneEnterpriseBoulevardMember" xlink:to="cli_OneEnterpriseBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneEnterpriseBoulevardMember_lbl" xml:lang="en-US">One Enterprise Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneEnterpriseBoulevardMember_lbl" xml:lang="en-US">One Enterprise Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneEnterpriseBoulevardMember_lbl" xml:lang="en-US">1 Enterprise Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SixtyOneSouthParamusRoadMember" xlink:label="cli_SixtyOneSouthParamusRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SixtyOneSouthParamusRoadMember" xlink:to="cli_SixtyOneSouthParamusRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SixtyOneSouthParamusRoadMember_lbl" xml:lang="en-US">Sixty One South Paramus Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SixtyOneSouthParamusRoadMember_lbl" xml:lang="en-US">Sixty One South Paramus Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SixtyOneSouthParamusRoadMember_lbl" xml:lang="en-US">61 South Paramus Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeHundredTiceBoulevardMember" xlink:label="cli_ThreeHundredTiceBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeHundredTiceBoulevardMember" xlink:to="cli_ThreeHundredTiceBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeHundredTiceBoulevardMember_lbl" xml:lang="en-US">Three Hundred Tice Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeHundredTiceBoulevardMember_lbl" xml:lang="en-US">Three Hundred Tice Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeHundredTiceBoulevardMember_lbl" xml:lang="en-US">300 Tice Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoIndependenceWayMember" xlink:label="cli_TwoIndependenceWayMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoIndependenceWayMember" xlink:to="cli_TwoIndependenceWayMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoIndependenceWayMember_lbl" xml:lang="en-US">2 Independence Way [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoIndependenceWayMember_lbl" xml:lang="en-US">Two Independence Way [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoIndependenceWayMember_lbl" xml:lang="en-US">2 Independence Way [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneThousandTwoHundredOneConnecticutAvenueNWMember" xlink:label="cli_OneThousandTwoHundredOneConnecticutAvenueNWMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneThousandTwoHundredOneConnecticutAvenueNWMember" xlink:to="cli_OneThousandTwoHundredOneConnecticutAvenueNWMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneThousandTwoHundredOneConnecticutAvenueNWMember_lbl" xml:lang="en-US">One Thousand Two Hundred One Connecticut Avenue NW [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneThousandTwoHundredOneConnecticutAvenueNWMember_lbl" xml:lang="en-US">One Thousand Two Hundred One Connecticut Avenue N W [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneThousandTwoHundredOneConnecticutAvenueNWMember_lbl" xml:lang="en-US">1201 Connecticut Avenue, NW [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredTwentyFiveBroadStreetMember" xlink:label="cli_OneHundredTwentyFiveBroadStreetMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredTwentyFiveBroadStreetMember" xlink:to="cli_OneHundredTwentyFiveBroadStreetMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredTwentyFiveBroadStreetMember_lbl" xml:lang="en-US">One Hundred Twenty Five Broad Street [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredTwentyFiveBroadStreetMember_lbl" xml:lang="en-US">One Hundred Twenty Five Broad Street [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredTwentyFiveBroadStreetMember_lbl" xml:lang="en-US">125 Broad Street [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NineThousandTwoHundredEdmonstonRoadMember" xlink:label="cli_NineThousandTwoHundredEdmonstonRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NineThousandTwoHundredEdmonstonRoadMember" xlink:to="cli_NineThousandTwoHundredEdmonstonRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NineThousandTwoHundredEdmonstonRoadMember_lbl" xml:lang="en-US">Nine Thousand Two Hundred Edmonston Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NineThousandTwoHundredEdmonstonRoadMember_lbl" xml:lang="en-US">Nine Thousand Two Hundred Edmonston Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NineThousandTwoHundredEdmonstonRoadMember_lbl" xml:lang="en-US">9200 Edmonston Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneThousandFourHundredLStreetNWMember" xlink:label="cli_OneThousandFourHundredLStreetNWMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneThousandFourHundredLStreetNWMember" xlink:to="cli_OneThousandFourHundredLStreetNWMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneThousandFourHundredLStreetNWMember_lbl" xml:lang="en-US">One Thousand Four Hundred L Street NW [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneThousandFourHundredLStreetNWMember_lbl" xml:lang="en-US">One Thousand Four Hundred L Street N W [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneThousandFourHundredLStreetNWMember_lbl" xml:lang="en-US">1400 L Street [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SixHundredParsippanyRoadMember" xlink:label="cli_SixHundredParsippanyRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SixHundredParsippanyRoadMember" xlink:to="cli_SixHundredParsippanyRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SixHundredParsippanyRoadMember_lbl" xml:lang="en-US">Six Hundred Parsippany Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SixHundredParsippanyRoadMember_lbl" xml:lang="en-US">Six Hundred Parsippany Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SixHundredParsippanyRoadMember_lbl" xml:lang="en-US">600 Parsippany Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FourFiveSixCenturyDriveMember" xlink:label="cli_FourFiveSixCenturyDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FourFiveSixCenturyDriveMember" xlink:to="cli_FourFiveSixCenturyDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FourFiveSixCenturyDriveMember_lbl" xml:lang="en-US">Four, Five, Six, Century Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FourFiveSixCenturyDriveMember_lbl" xml:lang="en-US">Four Five Six Century Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FourFiveSixCenturyDriveMember_lbl" xml:lang="en-US">4, 5, 6 Century Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AndoverPlaceMember" xlink:label="cli_AndoverPlaceMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AndoverPlaceMember" xlink:to="cli_AndoverPlaceMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AndoverPlaceMember_lbl" xml:lang="en-US">Andover Place [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AndoverPlaceMember_lbl" xml:lang="en-US">Andover Place [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AndoverPlaceMember_lbl" xml:lang="en-US">Andover Place [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoHundredTwentyTwoTwoHundredThirtyThreeMountAiryRoadMember" xlink:label="cli_TwoHundredTwentyTwoTwoHundredThirtyThreeMountAiryRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoHundredTwentyTwoTwoHundredThirtyThreeMountAiryRoadMember" xlink:to="cli_TwoHundredTwentyTwoTwoHundredThirtyThreeMountAiryRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoHundredTwentyTwoTwoHundredThirtyThreeMountAiryRoadMember_lbl" xml:lang="en-US">Two Hundred Twenty Two, Two Hundred Thirty Three Mount Airy Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoHundredTwentyTwoTwoHundredThirtyThreeMountAiryRoadMember_lbl" xml:lang="en-US">Two Hundred Twenty Two Two Hundred Thirty Three Mount Airy Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoHundredTwentyTwoTwoHundredThirtyThreeMountAiryRoadMember_lbl" xml:lang="en-US">222, 233 Mount Airy Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TenMountainviewRoadMember" xlink:label="cli_TenMountainviewRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TenMountainviewRoadMember" xlink:to="cli_TenMountainviewRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TenMountainviewRoadMember_lbl" xml:lang="en-US">Ten Mountainview Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TenMountainviewRoadMember_lbl" xml:lang="en-US">Ten Mountainview Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TenMountainviewRoadMember_lbl" xml:lang="en-US">10 Mountainview Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredWillowbrookRoadTwoThreeFourParagonMember" xlink:label="cli_OneHundredWillowbrookRoadTwoThreeFourParagonMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredWillowbrookRoadTwoThreeFourParagonMember" xlink:to="cli_OneHundredWillowbrookRoadTwoThreeFourParagonMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredWillowbrookRoadTwoThreeFourParagonMember_lbl" xml:lang="en-US">One Hundred Willowbrook Road, Two, Three, Four, Paragon [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredWillowbrookRoadTwoThreeFourParagonMember_lbl" xml:lang="en-US">One Hundred Willowbrook Road Two Three Four Paragon [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredWillowbrookRoadTwoThreeFourParagonMember_lbl" xml:lang="en-US">100 Willowbrook, 2, 3, 4 Paragon [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FourBeckerFarmRoadMember" xlink:label="cli_FourBeckerFarmRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FourBeckerFarmRoadMember" xlink:to="cli_FourBeckerFarmRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FourBeckerFarmRoadMember_lbl" xml:lang="en-US">Four Becker Farm Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FourBeckerFarmRoadMember_lbl" xml:lang="en-US">Four Becker Farm Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FourBeckerFarmRoadMember_lbl" xml:lang="en-US">4 Becker Farm Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredOneOneHundredThreeOneHundredFiveEisenhowerParkwayMember" xlink:label="cli_OneHundredOneOneHundredThreeOneHundredFiveEisenhowerParkwayMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredOneOneHundredThreeOneHundredFiveEisenhowerParkwayMember" xlink:to="cli_OneHundredOneOneHundredThreeOneHundredFiveEisenhowerParkwayMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredOneOneHundredThreeOneHundredFiveEisenhowerParkwayMember_lbl" xml:lang="en-US">One Hundred One, One Hundred Three, One Hundred Five Eisenhower Parkway [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredOneOneHundredThreeOneHundredFiveEisenhowerParkwayMember_lbl" xml:lang="en-US">One Hundred One One Hundred Three One Hundred Five Eisenhower Parkway [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredOneOneHundredThreeOneHundredFiveEisenhowerParkwayMember_lbl" xml:lang="en-US">101, 103, 105 Eisenhower Parkway [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_CapitalOfficeParkIvyLaneMember" xlink:label="cli_CapitalOfficeParkIvyLaneMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_CapitalOfficeParkIvyLaneMember" xlink:to="cli_CapitalOfficeParkIvyLaneMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_CapitalOfficeParkIvyLaneMember_lbl" xml:lang="en-US">Capital Office Park, Ivy Lane [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_CapitalOfficeParkIvyLaneMember_lbl" xml:lang="en-US">Capital Office Park Ivy Lane [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_CapitalOfficeParkIvyLaneMember_lbl" xml:lang="en-US">Capital Office Park, Ivy Lane [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredWalnutAvenueMember" xlink:label="cli_OneHundredWalnutAvenueMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredWalnutAvenueMember" xlink:to="cli_OneHundredWalnutAvenueMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredWalnutAvenueMember_lbl" xml:lang="en-US">100 Walnut Avenue</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredWalnutAvenueMember_lbl" xml:lang="en-US">One Hundred Walnut Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredWalnutAvenueMember_lbl" xml:lang="en-US">100 Walnut Avenue [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwentyCommerceDriveMember" xlink:label="cli_TwentyCommerceDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwentyCommerceDriveMember" xlink:to="cli_TwentyCommerceDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwentyCommerceDriveMember_lbl" xml:lang="en-US">Twenty Commerce Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwentyCommerceDriveMember_lbl" xml:lang="en-US">Twenty Commerce Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwentyCommerceDriveMember_lbl" xml:lang="en-US">20 Commerce Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FourThousandTwoHundredParliamentPlaceMember" xlink:label="cli_FourThousandTwoHundredParliamentPlaceMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FourThousandTwoHundredParliamentPlaceMember" xlink:to="cli_FourThousandTwoHundredParliamentPlaceMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FourThousandTwoHundredParliamentPlaceMember_lbl" xml:lang="en-US">Four Thousand Two Hundred Parliament Place [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FourThousandTwoHundredParliamentPlaceMember_lbl" xml:lang="en-US">Four Thousand Two Hundred Parliament Place [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NotesReceivableThreeMember_lbl" xml:lang="en-US">Notes Receivable Three [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ReceivableTypeDomain_lbl" xml:lang="en-US">Receivable [Domain]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_InterestFreeNotesReceivableMember_lbl" xml:lang="en-US">Interest Free Notes Receivable [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_InterestFreeNotesReceivableMember_lbl" xml:lang="en-US">Interest Free Notes Receivable [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_InterestFreeNotesReceivableMember_lbl" xml:lang="en-US">Interest-Free Notes Receivable [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NonrecurringAdjustmentAxis" xlink:label="us-gaap_NonrecurringAdjustmentAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonrecurringAdjustmentAxis" xlink:to="us-gaap_NonrecurringAdjustmentAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NonrecurringAdjustmentAxis_lbl" xml:lang="en-US">Nonrecurring Adjustment [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NonrecurringAdjustmentDomain" xlink:label="us-gaap_NonrecurringAdjustmentDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonrecurringAdjustmentDomain" xlink:to="us-gaap_NonrecurringAdjustmentDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NonrecurringAdjustmentDomain_lbl" xml:lang="en-US">Nonrecurring Adjustment [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NonrecurringAdjustmentDomain_lbl" xml:lang="en-US">Nonrecurring Adjustment [Domain]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AcquisitionRelatedCostsMember" xlink:label="us-gaap_AcquisitionRelatedCostsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AcquisitionRelatedCostsMember" xlink:to="us-gaap_AcquisitionRelatedCostsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AcquisitionRelatedCostsMember_lbl" xml:lang="en-US">Acquisition Related Costs [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AcquisitionRelatedCostsMember_lbl" xml:lang="en-US">Acquisition-related Costs [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AboveMarketLeasesMember" xlink:label="us-gaap_AboveMarketLeasesMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AboveMarketLeasesMember" xlink:to="us-gaap_AboveMarketLeasesMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AboveMarketLeasesMember_lbl" xml:lang="en-US">Above Market Leases [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AboveMarketLeasesMember_lbl" xml:lang="en-US">Above Market Leases [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_BelowMarketLeaseIntangiblesMember" xlink:label="cli_BelowMarketLeaseIntangiblesMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_BelowMarketLeaseIntangiblesMember" xlink:to="cli_BelowMarketLeaseIntangiblesMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_BelowMarketLeaseIntangiblesMember_lbl" xml:lang="en-US">Below Market Lease Intangibles [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_BelowMarketLeaseIntangiblesMember_lbl" xml:lang="en-US">Below Market Lease Intangibles [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_BelowMarketLeaseIntangiblesMember_lbl" xml:lang="en-US">Acquired Below-Market Lease Intangibles [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="us-gaap_InterestRateSwapMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestRateSwapMember" xlink:to="us-gaap_InterestRateSwapMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestRateSwapMember_lbl" xml:lang="en-US">Interest Rate Swap [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InterestRateSwapMember_lbl" xml:lang="en-US">Interest Rate Swaps [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="us-gaap_BalanceSheetLocationAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BalanceSheetLocationAxis" xlink:to="us-gaap_BalanceSheetLocationAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BalanceSheetLocationAxis_lbl" xml:lang="en-US">Balance Sheet Location [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="us-gaap_BalanceSheetLocationDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BalanceSheetLocationDomain" xlink:to="us-gaap_BalanceSheetLocationDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BalanceSheetLocationDomain_lbl" xml:lang="en-US">Balance Sheet Location [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BalanceSheetLocationDomain_lbl" xml:lang="en-US">Balance Sheet Location [Domain]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_DeferredChargesGoodwillAndOtherAssetsMember" xlink:label="cli_DeferredChargesGoodwillAndOtherAssetsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_DeferredChargesGoodwillAndOtherAssetsMember" xlink:to="cli_DeferredChargesGoodwillAndOtherAssetsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_DeferredChargesGoodwillAndOtherAssetsMember_lbl" xml:lang="en-US">Deferred Charges, Goodwill And Other Assets [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_DeferredChargesGoodwillAndOtherAssetsMember_lbl" xml:lang="en-US">Deferred Charges Goodwill And Other Assets [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_DeferredChargesGoodwillAndOtherAssetsMember_lbl" xml:lang="en-US">Deferred Charges, Goodwill And Other Assets [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="us-gaap_IncomeStatementLocationAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementLocationAxis" xlink:to="us-gaap_IncomeStatementLocationAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeStatementLocationAxis_lbl" xml:lang="en-US">Income Statement Location [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="us-gaap_IncomeStatementLocationDomain" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementLocationDomain" xlink:to="us-gaap_IncomeStatementLocationDomain_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeStatementLocationDomain_lbl" xml:lang="en-US">Income Statement Location [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeStatementLocationDomain_lbl" xml:lang="en-US">Income Statement Location [Domain]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InterestExpenseMember" xlink:label="us-gaap_InterestExpenseMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpenseMember" xlink:to="us-gaap_InterestExpenseMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestExpenseMember_lbl" xml:lang="en-US">Interest Expense [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InterestExpenseMember_lbl" xml:lang="en-US">Interest Expense [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_InterestAndOtherInvestmentIncomeLossMember" xlink:label="cli_InterestAndOtherInvestmentIncomeLossMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_InterestAndOtherInvestmentIncomeLossMember" xlink:to="cli_InterestAndOtherInvestmentIncomeLossMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_InterestAndOtherInvestmentIncomeLossMember_lbl" xml:lang="en-US">Interest And Other Investment Income (Loss) [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_InterestAndOtherInvestmentIncomeLossMember_lbl" xml:lang="en-US">Interest And Other Investment Income Loss [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_InterestAndOtherInvestmentIncomeLossMember_lbl" xml:lang="en-US">Interest And Other Investment Income (Loss) [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoPointFiveZeroZeroPercentSeniorUnsecuredNotesDueDecemberFifteenTwoThousandSeventeenMember" xlink:label="cli_TwoPointFiveZeroZeroPercentSeniorUnsecuredNotesDueDecemberFifteenTwoThousandSeventeenMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoPointFiveZeroZeroPercentSeniorUnsecuredNotesDueDecemberFifteenTwoThousandSeventeenMember" xlink:to="cli_TwoPointFiveZeroZeroPercentSeniorUnsecuredNotesDueDecemberFifteenTwoThousandSeventeenMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoPointFiveZeroZeroPercentSeniorUnsecuredNotesDueDecemberFifteenTwoThousandSeventeenMember_lbl" xml:lang="en-US">Two Point Five Zero Zero Percent Senior Unsecured Notes Due December Fifteen Two Thousand Seventeen [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoPointFiveZeroZeroPercentSeniorUnsecuredNotesDueDecemberFifteenTwoThousandSeventeenMember_lbl" xml:lang="en-US">Two Point Five Zero Zero Percent Senior Unsecured Notes Due December Fifteen Two Thousand Seventeen [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoPointFiveZeroZeroPercentSeniorUnsecuredNotesDueDecemberFifteenTwoThousandSeventeenMember_lbl" xml:lang="en-US">2.500% Senior Unsecured Notes Due December 15, 2017 [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FourPointFiveZeroZeroPercentSeniorUnsecuredNotesDueAprilEighteenTwoThousandTwentyTwoMember" xlink:label="cli_FourPointFiveZeroZeroPercentSeniorUnsecuredNotesDueAprilEighteenTwoThousandTwentyTwoMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FourPointFiveZeroZeroPercentSeniorUnsecuredNotesDueAprilEighteenTwoThousandTwentyTwoMember" xlink:to="cli_FourPointFiveZeroZeroPercentSeniorUnsecuredNotesDueAprilEighteenTwoThousandTwentyTwoMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FourPointFiveZeroZeroPercentSeniorUnsecuredNotesDueAprilEighteenTwoThousandTwentyTwoMember_lbl" xml:lang="en-US">Four Point Five Zero Zero Percent Senior Unsecured Notes Due April Eighteen Two Thousand Twenty Two [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FourPointFiveZeroZeroPercentSeniorUnsecuredNotesDueAprilEighteenTwoThousandTwentyTwoMember_lbl" xml:lang="en-US">Four Point Five Zero Zero Percent Senior Unsecured Notes Due April Eighteen Two Thousand Twenty Two [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FourPointFiveZeroZeroPercentSeniorUnsecuredNotesDueAprilEighteenTwoThousandTwentyTwoMember_lbl" xml:lang="en-US">4.500% Senior Unsecured Notes Due April 18, 2022 [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreePointOneFiveZeroPercentSeniorUnsecuredNotesDueMayFifteenthTwoThousandTwentyThreeMember" xlink:label="cli_ThreePointOneFiveZeroPercentSeniorUnsecuredNotesDueMayFifteenthTwoThousandTwentyThreeMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreePointOneFiveZeroPercentSeniorUnsecuredNotesDueMayFifteenthTwoThousandTwentyThreeMember" xlink:to="cli_ThreePointOneFiveZeroPercentSeniorUnsecuredNotesDueMayFifteenthTwoThousandTwentyThreeMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreePointOneFiveZeroPercentSeniorUnsecuredNotesDueMayFifteenthTwoThousandTwentyThreeMember_lbl" xml:lang="en-US">3.150% Senior Unsecured Note, Due May 15, 2023 [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreePointOneFiveZeroPercentSeniorUnsecuredNotesDueMayFifteenthTwoThousandTwentyThreeMember_lbl" xml:lang="en-US">Three Point One Five Zero Percent Senior Unsecured Notes Due May Fifteenth Two Thousand Twenty Three [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreePointOneFiveZeroPercentSeniorUnsecuredNotesDueMayFifteenthTwoThousandTwentyThreeMember_lbl" xml:lang="en-US">3.150% Senior Unsecured Notes, Due May 15, 2023 [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_UnsecuredTermLoanMember" xlink:label="cli_UnsecuredTermLoanMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_UnsecuredTermLoanMember" xlink:to="cli_UnsecuredTermLoanMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_UnsecuredTermLoanMember_lbl" xml:lang="en-US">Unsecured Term Loan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_UnsecuredTermLoanMember_lbl" xml:lang="en-US">Unsecured Term Loan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_UnsecuredTermLoanMember_lbl" xml:lang="en-US">Unsecured Term Loan [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FivePointEightZeroZeroPercentSeniorUnsecuredNotesDueJanuaryFifteenTwoThousandSixteenMember" xlink:label="cli_FivePointEightZeroZeroPercentSeniorUnsecuredNotesDueJanuaryFifteenTwoThousandSixteenMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FivePointEightZeroZeroPercentSeniorUnsecuredNotesDueJanuaryFifteenTwoThousandSixteenMember" xlink:to="cli_FivePointEightZeroZeroPercentSeniorUnsecuredNotesDueJanuaryFifteenTwoThousandSixteenMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FivePointEightZeroZeroPercentSeniorUnsecuredNotesDueJanuaryFifteenTwoThousandSixteenMember_lbl" xml:lang="en-US">5.800% Senior Unsecured Notes, due January 15, 2016</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FivePointEightZeroZeroPercentSeniorUnsecuredNotesDueJanuaryFifteenTwoThousandSixteenMember_lbl" xml:lang="en-US">Five Point Eight Zero Zero Percent Senior Unsecured Notes Due January Fifteen Two Thousand Sixteen [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FivePointEightZeroZeroPercentSeniorUnsecuredNotesDueJanuaryFifteenTwoThousandSixteenMember_lbl" xml:lang="en-US">5.800% Senior Unsecured Notes, Due January 15, 2016 [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwentySeventeenTermLoanMember" xlink:label="cli_TwentySeventeenTermLoanMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwentySeventeenTermLoanMember" xlink:to="cli_TwentySeventeenTermLoanMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwentySeventeenTermLoanMember_lbl" xml:lang="en-US">Twenty Seventeen Term Loan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwentySeventeenTermLoanMember_lbl" xml:lang="en-US">Twenty Seventeen Term Loan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwentySeventeenTermLoanMember_lbl" xml:lang="en-US">2017 Term Loan [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_IncrementalCommitmentsMember" xlink:label="cli_IncrementalCommitmentsMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_IncrementalCommitmentsMember_lbl" xml:lang="en-US">Incremental Commitments [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ChaseAtOverlookRidgeAndChaseIiMember_lbl" xml:lang="en-US">Chase At Overlook Ridge And Chase II [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ChaseAtOverlookRidgeAndChaseIiMember_lbl" xml:lang="en-US">The Chase At Overlook Ridge And Chase II [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredOneHudsonStreetMember_lbl" xml:lang="en-US">One Hundred One Hudson Street [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredOneHudsonStreetMember_lbl" xml:lang="en-US">101 Hudson Street [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ShortHillsPortfolioMember_lbl" xml:lang="en-US">Short Hills Portfolio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ShortHillsPortfolioMember_lbl" xml:lang="en-US">Short Hills Portfolio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ShortHillsPortfolioMember_lbl" xml:lang="en-US">Short Hills Portfolio [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredFiftyMainStreetMember" xlink:label="cli_OneHundredFiftyMainStreetMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredFiftyMainStreetMember_lbl" xml:lang="en-US">150 Main St [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredFiftyMainStreetMember_lbl" xml:lang="en-US">One Hundred Fifty Main Street [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredFiftyMainStreetMember_lbl" xml:lang="en-US">150 Main St [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PortImperialHotelDevelopmentMember" xlink:label="cli_PortImperialHotelDevelopmentMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PortImperialHotelDevelopmentMember" xlink:to="cli_PortImperialHotelDevelopmentMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PortImperialHotelDevelopmentMember_lbl" xml:lang="en-US">Port Imperial Hotel Development [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PortImperialHotelDevelopmentMember_lbl" xml:lang="en-US">Port Imperial Hotel Development [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PortImperialHotelDevelopmentMember_lbl" xml:lang="en-US">Port Imperial Hotel Development [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PortImperialSouthElevenDevelopmentMember" xlink:label="cli_PortImperialSouthElevenDevelopmentMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PortImperialSouthElevenDevelopmentMember" xlink:to="cli_PortImperialSouthElevenDevelopmentMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PortImperialSouthElevenDevelopmentMember_lbl" xml:lang="en-US">Port Imperial South Eleven Development [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PortImperialSouthElevenDevelopmentMember_lbl" xml:lang="en-US">Port Imperial South Eleven Development [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PortImperialSouthElevenDevelopmentMember_lbl" xml:lang="en-US">Port Imperial South 11 Development [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneOneOneRiverRealtyMember" xlink:label="cli_OneOneOneRiverRealtyMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneOneOneRiverRealtyMember" xlink:to="cli_OneOneOneRiverRealtyMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneOneOneRiverRealtyMember_lbl" xml:lang="en-US">One One One River Realty [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneOneOneRiverRealtyMember_lbl" xml:lang="en-US">One One One River Realty [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneOneOneRiverRealtyMember_lbl" xml:lang="en-US">111 River Realty [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TaxPeriodAxis_lbl" xml:lang="en-US">Tax Period [Axis]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TaxPeriodDomain_lbl" xml:lang="en-US">Tax Period [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_TaxPeriodDomain_lbl" xml:lang="en-US">Tax Period [Domain]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TaxYearOneMember" xlink:label="cli_TaxYearOneMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TaxYearOneMember_lbl" xml:lang="en-US">Tax Year One [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TaxYearOneMember_lbl" xml:lang="en-US">Tax Year One [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TaxYearOneMember_lbl" xml:lang="en-US">Tax Year 1 [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TaxYearTwoMember" xlink:label="cli_TaxYearTwoMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TaxYearTwoMember_lbl" xml:lang="en-US">Tax Year Two [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TaxYearTwoMember_lbl" xml:lang="en-US">Tax Year Two [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TaxYearTwoMember_lbl" xml:lang="en-US">Tax Year 2 [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TaxYearThreeMember" xlink:label="cli_TaxYearThreeMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TaxYearThreeMember_lbl" xml:lang="en-US">Tax Year Three [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TaxYearThreeMember_lbl" xml:lang="en-US">Tax Year Three [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TaxYearThreeMember_lbl" xml:lang="en-US">Tax Year 3 [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TaxYearFourMember" xlink:label="cli_TaxYearFourMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TaxYearFourMember_lbl" xml:lang="en-US">Tax Year Four [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoThousandSixteenTimeBasedVestingLongTermIncentivePlanMember_lbl" xml:lang="en-US">2016 TBV LTIP Units [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoThousandSixteenOutperformancePlanMember_lbl" xml:lang="en-US">Two Thousand Sixteen Outperformance Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoThousandSixteenOutperformancePlanMember_lbl" xml:lang="en-US">2016 OPP [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoThousandSixteenPerformanceBasedVestingLongTermIncentivePlanMember_lbl" xml:lang="en-US">Two Thousand Sixteen Performance-Based Vesting Long-Term Incentive Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoThousandSixteenPerformanceBasedVestingLongTermIncentivePlanMember_lbl" xml:lang="en-US">Two Thousand Sixteen Performance Based Vesting Long Term Incentive Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoThousandSixteenPerformanceBasedVestingLongTermIncentivePlanMember_lbl" xml:lang="en-US">2016 PBV LTIP Units [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoThousandSeventeenLongTermIncentivePlanMember" xlink:label="cli_TwoThousandSeventeenLongTermIncentivePlanMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoThousandSeventeenLongTermIncentivePlanMember_lbl" xml:lang="en-US">Two Thousand Seventeen Long-Term Incentive Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoThousandSeventeenLongTermIncentivePlanMember_lbl" xml:lang="en-US">Two Thousand Seventeen Long Term Incentive Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoThousandSeventeenLongTermIncentivePlanMember_lbl" xml:lang="en-US">2017 LTIP Awards [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoThousandSeventeenOutperformancePlanMember_lbl" xml:lang="en-US">Two Thousand Seventeen Outperformance Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoThousandSeventeenOutperformancePlanMember_lbl" xml:lang="en-US">Two Thousand Seventeen Outperformance Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoThousandSeventeenOutperformancePlanMember_lbl" xml:lang="en-US">2017 OPP [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoThousandSeventeenPerformanceBasedVestingLongTermIncentivePlanMember" xlink:label="cli_TwoThousandSeventeenPerformanceBasedVestingLongTermIncentivePlanMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoThousandSeventeenPerformanceBasedVestingLongTermIncentivePlanMember" xlink:to="cli_TwoThousandSeventeenPerformanceBasedVestingLongTermIncentivePlanMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoThousandSeventeenPerformanceBasedVestingLongTermIncentivePlanMember_lbl" xml:lang="en-US">Two Thousand Seventeen Performance-Based Vesting Long-Term Incentive Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoThousandSeventeenPerformanceBasedVestingLongTermIncentivePlanMember_lbl" xml:lang="en-US">Two Thousand Seventeen Performance Based Vesting Long Term Incentive Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoThousandSeventeenPerformanceBasedVestingLongTermIncentivePlanMember_lbl" xml:lang="en-US">2017 PBV LTIP Units [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoThousandSeventeenTimeBasedVestingLongTermIncentivePlanMember" xlink:label="cli_TwoThousandSeventeenTimeBasedVestingLongTermIncentivePlanMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoThousandSeventeenTimeBasedVestingLongTermIncentivePlanMember" xlink:to="cli_TwoThousandSeventeenTimeBasedVestingLongTermIncentivePlanMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoThousandSeventeenTimeBasedVestingLongTermIncentivePlanMember_lbl" xml:lang="en-US">Two Thousand Seventeen Time-Based Vesting Long-Term Incentive Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoThousandSeventeenTimeBasedVestingLongTermIncentivePlanMember_lbl" xml:lang="en-US">Two Thousand Seventeen Time Based Vesting Long Term Incentive Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoThousandSeventeenTimeBasedVestingLongTermIncentivePlanMember_lbl" xml:lang="en-US">2017 TBV LTIP Units [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TimeVestingOptionsMember" xlink:label="cli_TimeVestingOptionsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TimeVestingOptionsMember" xlink:to="cli_TimeVestingOptionsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TimeVestingOptionsMember_lbl" xml:lang="en-US">Time Vesting Options [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TimeVestingOptionsMember_lbl" xml:lang="en-US">Time Vesting Options [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TimeVestingOptionsMember_lbl" xml:lang="en-US">Time Vesting Options [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PriceVestingOptionsMember" xlink:label="cli_PriceVestingOptionsMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PriceVestingOptionsMember_lbl" xml:lang="en-US">Price Vesting Options [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PriceVestingOptionsMember_lbl" xml:lang="en-US">Price Vesting Options [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PriceVestingOptionsMember_lbl" xml:lang="en-US">Price Vesting Options [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_MessieurRudinAndMessieurDemarcoMember" xlink:label="cli_MessieurRudinAndMessieurDemarcoMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_MessieurRudinAndMessieurDemarcoMember_lbl" xml:lang="en-US">Messieur Rudin And Messieur DeMarco [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_MessieurRudinAndMessieurDemarcoMember_lbl" xml:lang="en-US">Messieur Rudin And Messieur Demarco [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_MessieurRudinAndMessieurDemarcoMember_lbl" xml:lang="en-US">Messr Rudin And Messr DeMarco [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CorporateAndOtherMember" xlink:label="us-gaap_CorporateAndOtherMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CorporateAndOtherMember_lbl" xml:lang="en-US">Corporate And Other [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CorporateAndOtherMember_lbl" xml:lang="en-US">Corporate &amp; Other [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RetailSiteMember" xlink:label="us-gaap_RetailSiteMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetailSiteMember" xlink:to="us-gaap_RetailSiteMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetailSiteMember_lbl" xml:lang="en-US">Retail Site [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RetailSiteMember_lbl" xml:lang="en-US">Retail [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneBridgePlazaMember" xlink:label="cli_OneBridgePlazaMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneBridgePlazaMember_lbl" xml:lang="en-US">One Bridge Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneBridgePlazaMember_lbl" xml:lang="en-US">One Bridge Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneBridgePlazaMember_lbl" xml:lang="en-US">One Bridge Plaza [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoThousandOneHundredFifteenLinwoodAvenueMember" xlink:label="cli_TwoThousandOneHundredFifteenLinwoodAvenueMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoThousandOneHundredFifteenLinwoodAvenueMember" xlink:to="cli_TwoThousandOneHundredFifteenLinwoodAvenueMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoThousandOneHundredFifteenLinwoodAvenueMember_lbl" xml:lang="en-US">Two Thousand One Hundred Fifteen Linwood Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoThousandOneHundredFifteenLinwoodAvenueMember_lbl" xml:lang="en-US">Two Thousand One Hundred Fifteen Linwood Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoThousandOneHundredFifteenLinwoodAvenueMember_lbl" xml:lang="en-US">2115 Linwood Avenue [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredFiftyJFKennedyParkwayMember_lbl" xml:lang="en-US">One Hundred Fifty J.F. Kennedy Parkway [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredFiftyJFKennedyParkwayMember_lbl" xml:lang="en-US">One Hundred Fifty J F Kennedy Parkway [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredFiftyJFKennedyParkwayMember_lbl" xml:lang="en-US">150 J.F. Kennedy Parkway [Member]</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SeventyFiveLivingstonAvenueMember" xlink:to="cli_SeventyFiveLivingstonAvenueMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SeventyFiveLivingstonAvenueMember_lbl" xml:lang="en-US">Seventy Five Livingston Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SeventyFiveLivingstonAvenueMember_lbl" xml:lang="en-US">Seventy Five Livingston Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SeventyFiveLivingstonAvenueMember_lbl" xml:lang="en-US">75 Livingston Avenue [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiftyOneJ.f.KennedyParkwayMember_lbl" xml:lang="en-US">Fifty One J.F. Kennedy Parkway [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiftyOneJ.f.KennedyParkwayMember_lbl" xml:lang="en-US">Fifty One J.f. Kennedy Parkway [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiftyOneJ.f.KennedyParkwayMember_lbl" xml:lang="en-US">51 J.F. Kennedy Parkway [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredOneJ.f.KennedyParkwayMember_lbl" xml:lang="en-US">One Hundred One J.F. Kennedy Parkway [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredOneJ.f.KennedyParkwayMember_lbl" xml:lang="en-US">One Hundred One J.f. Kennedy Parkway [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredOneJ.f.KennedyParkwayMember_lbl" xml:lang="en-US">101 J.F. Kennedy Parkway [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredThreeJ.f.KennedyParkwayMember" xlink:label="cli_OneHundredThreeJ.f.KennedyParkwayMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredThreeJ.f.KennedyParkwayMember_lbl" xml:lang="en-US">One Hundred Three J.F. Kennedy Parkway [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredThreeJ.f.KennedyParkwayMember_lbl" xml:lang="en-US">One Hundred Three J.f. Kennedy Parkway [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredThreeJ.f.KennedyParkwayMember_lbl" xml:lang="en-US">103 J.F. Kennedy Parkway [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_HarborsidePlazaOneMember" xlink:label="cli_HarborsidePlazaOneMember" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_HarborsidePlazaOneMember_lbl" xml:lang="en-US">Harborside Plaza One [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_HarborsidePlazaOneMember_lbl" xml:lang="en-US">Harborside Plaza 1 [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_HarborsidePlazaTwoMember_lbl" xml:lang="en-US">Harborside Plaza Two [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_HarborsidePlazaTwoMember_lbl" xml:lang="en-US">Harborside Plaza 2 [Member]</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_HarborsidePlazaThreeMember" xlink:to="cli_HarborsidePlazaThreeMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_HarborsidePlazaThreeMember_lbl" xml:lang="en-US">Harborside Plaza 3 [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_HarborsidePlazaThreeMember_lbl" xml:lang="en-US">Harborside Plaza Three [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_HarborsidePlazaThreeMember_lbl" xml:lang="en-US">Harborside Plaza 3 [Member]</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_HarborsidePlazaFouraMember" xlink:to="cli_HarborsidePlazaFouraMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_HarborsidePlazaFouraMember_lbl" xml:lang="en-US">Harborside Plaza 4A [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_HarborsidePlazaFouraMember_lbl" xml:lang="en-US">Harborside Plaza Foura [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_HarborsidePlazaFouraMember_lbl" xml:lang="en-US">Harborside Plaza 4A [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredAvenueAtPortImperialMember" xlink:label="cli_OneHundredAvenueAtPortImperialMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredAvenueAtPortImperialMember" xlink:to="cli_OneHundredAvenueAtPortImperialMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredAvenueAtPortImperialMember_lbl" xml:lang="en-US">One Hundred Avenue At Port Imperial [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredAvenueAtPortImperialMember_lbl" xml:lang="en-US">One Hundred Avenue At Port Imperial [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredAvenueAtPortImperialMember_lbl" xml:lang="en-US">100 Avenue At Port Imperial [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FiveHundredAvenueAtPortImperialMember" xlink:label="cli_FiveHundredAvenueAtPortImperialMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FiveHundredAvenueAtPortImperialMember" xlink:to="cli_FiveHundredAvenueAtPortImperialMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiveHundredAvenueAtPortImperialMember_lbl" xml:lang="en-US">500 Avenue At Port Imperial [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiveHundredAvenueAtPortImperialMember_lbl" xml:lang="en-US">Five Hundred Avenue At Port Imperial [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiveHundredAvenueAtPortImperialMember_lbl" xml:lang="en-US">500 Avenue At Port Imperial [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SixHundredHorizonDriveMember" xlink:label="cli_SixHundredHorizonDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SixHundredHorizonDriveMember" xlink:to="cli_SixHundredHorizonDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SixHundredHorizonDriveMember_lbl" xml:lang="en-US">Six Hundred Horizon Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SixHundredHorizonDriveMember_lbl" xml:lang="en-US">Six Hundred Horizon Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SixHundredHorizonDriveMember_lbl" xml:lang="en-US">600 Horizon Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SevenHundredHorizonDriveMember" xlink:label="cli_SevenHundredHorizonDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SevenHundredHorizonDriveMember" xlink:to="cli_SevenHundredHorizonDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SevenHundredHorizonDriveMember_lbl" xml:lang="en-US">Seven Hundred Horizon Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SevenHundredHorizonDriveMember_lbl" xml:lang="en-US">Seven Hundred Horizon Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SevenHundredHorizonDriveMember_lbl" xml:lang="en-US">700 Horizon Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredOverlookCenterMember" xlink:label="cli_OneHundredOverlookCenterMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredOverlookCenterMember" xlink:to="cli_OneHundredOverlookCenterMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredOverlookCenterMember_lbl" xml:lang="en-US">One Hundred Overlook Center [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredOverlookCenterMember_lbl" xml:lang="en-US">One Hundred Overlook Center [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredOverlookCenterMember_lbl" xml:lang="en-US">100 Overlook Center [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FiveVaughnDriveMember" xlink:label="cli_FiveVaughnDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FiveVaughnDriveMember" xlink:to="cli_FiveVaughnDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiveVaughnDriveMember_lbl" xml:lang="en-US">Five Vaughn Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiveVaughnDriveMember_lbl" xml:lang="en-US">Five Vaughn Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiveVaughnDriveMember_lbl" xml:lang="en-US">5 Vaughn Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeHundredThirtyThreeThornallStreetMember" xlink:label="cli_ThreeHundredThirtyThreeThornallStreetMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeHundredThirtyThreeThornallStreetMember" xlink:to="cli_ThreeHundredThirtyThreeThornallStreetMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeHundredThirtyThreeThornallStreetMember_lbl" xml:lang="en-US">Three Hundred Thirty Three Thornall Street [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeHundredThirtyThreeThornallStreetMember_lbl" xml:lang="en-US">Three Hundred Thirty Three Thornall Street [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeHundredThirtyThreeThornallStreetMember_lbl" xml:lang="en-US">333 Thornall Street [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeHundredFortyThreeThornallStreetMember" xlink:label="cli_ThreeHundredFortyThreeThornallStreetMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeHundredFortyThreeThornallStreetMember" xlink:to="cli_ThreeHundredFortyThreeThornallStreetMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeHundredFortyThreeThornallStreetMember_lbl" xml:lang="en-US">Three Hundred Forty Three Thornall Street [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeHundredFortyThreeThornallStreetMember_lbl" xml:lang="en-US">Three Hundred Forty Three Thornall Street [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeHundredFortyThreeThornallStreetMember_lbl" xml:lang="en-US">343 Thornall Street [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RichmondCourtMember" xlink:label="cli_RichmondCourtMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RichmondCourtMember" xlink:to="cli_RichmondCourtMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RichmondCourtMember_lbl" xml:lang="en-US">Richmond Court [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RichmondCourtMember_lbl" xml:lang="en-US">Richmond Court [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RichmondCourtMember_lbl" xml:lang="en-US">Richmond Court [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_RiverwatchCommonsMember" xlink:label="cli_RiverwatchCommonsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_RiverwatchCommonsMember" xlink:to="cli_RiverwatchCommonsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_RiverwatchCommonsMember_lbl" xml:lang="en-US">Riverwatch Commons [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_RiverwatchCommonsMember_lbl" xml:lang="en-US">Riverwatch Commons [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_RiverwatchCommonsMember_lbl" xml:lang="en-US">Riverwatch Commons [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FiveHundredCollegeRoadEastMember" xlink:label="cli_FiveHundredCollegeRoadEastMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FiveHundredCollegeRoadEastMember" xlink:to="cli_FiveHundredCollegeRoadEastMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiveHundredCollegeRoadEastMember_lbl" xml:lang="en-US">Five Hundred College Road East [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiveHundredCollegeRoadEastMember_lbl" xml:lang="en-US">Five Hundred College Road East [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiveHundredCollegeRoadEastMember_lbl" xml:lang="en-US">500 College Road East [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FiveHundredEightyOneMainStreetMember" xlink:label="cli_FiveHundredEightyOneMainStreetMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FiveHundredEightyOneMainStreetMember" xlink:to="cli_FiveHundredEightyOneMainStreetMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiveHundredEightyOneMainStreetMember_lbl" xml:lang="en-US">Five Hundred Eighty One Main Street [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiveHundredEightyOneMainStreetMember_lbl" xml:lang="en-US">Five Hundred Eighty One Main Street [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiveHundredEightyOneMainStreetMember_lbl" xml:lang="en-US">581 Main Street [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneRiverCenterBuildingOneMember" xlink:label="cli_OneRiverCenterBuildingOneMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneRiverCenterBuildingOneMember" xlink:to="cli_OneRiverCenterBuildingOneMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneRiverCenterBuildingOneMember_lbl" xml:lang="en-US">One River Center, Building 1 [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneRiverCenterBuildingOneMember_lbl" xml:lang="en-US">One River Center Building One [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneRiverCenterBuildingOneMember_lbl" xml:lang="en-US">One River Center, Building 1 [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneRiverCenterBuildingTwoMember" xlink:label="cli_OneRiverCenterBuildingTwoMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneRiverCenterBuildingTwoMember" xlink:to="cli_OneRiverCenterBuildingTwoMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneRiverCenterBuildingTwoMember_lbl" xml:lang="en-US">One River Center, Building 2 [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneRiverCenterBuildingTwoMember_lbl" xml:lang="en-US">One River Center Building Two [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneRiverCenterBuildingTwoMember_lbl" xml:lang="en-US">One River Center, Building 2 [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneRiverCenterBuildingThreeMember" xlink:label="cli_OneRiverCenterBuildingThreeMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneRiverCenterBuildingThreeMember" xlink:to="cli_OneRiverCenterBuildingThreeMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneRiverCenterBuildingThreeMember_lbl" xml:lang="en-US">One River Center, Building 3 [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneRiverCenterBuildingThreeMember_lbl" xml:lang="en-US">One River Center Building Three [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneRiverCenterBuildingThreeMember_lbl" xml:lang="en-US">One River Center, Building 3 [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeThousandSixHundredRouteSixtySixMember" xlink:label="cli_ThreeThousandSixHundredRouteSixtySixMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeThousandSixHundredRouteSixtySixMember" xlink:to="cli_ThreeThousandSixHundredRouteSixtySixMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeThousandSixHundredRouteSixtySixMember_lbl" xml:lang="en-US">Three Thousand Six Hundred Route Sixty Six [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeThousandSixHundredRouteSixtySixMember_lbl" xml:lang="en-US">Three Thousand Six Hundred Route Sixty Six [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeThousandSixHundredRouteSixtySixMember_lbl" xml:lang="en-US">3600 Route 66 [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredSchultzDriveMember" xlink:label="cli_OneHundredSchultzDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredSchultzDriveMember" xlink:to="cli_OneHundredSchultzDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredSchultzDriveMember_lbl" xml:lang="en-US">One Hundred Schultz Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredSchultzDriveMember_lbl" xml:lang="en-US">One Hundred Schultz Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredSchultzDriveMember_lbl" xml:lang="en-US">100 Schultz Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoHundredSchultzDriveMember" xlink:label="cli_TwoHundredSchultzDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoHundredSchultzDriveMember" xlink:to="cli_TwoHundredSchultzDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoHundredSchultzDriveMember_lbl" xml:lang="en-US">Two Hundred Schultz Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoHundredSchultzDriveMember_lbl" xml:lang="en-US">Two Hundred Schultz Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoHundredSchultzDriveMember_lbl" xml:lang="en-US">200 Schultz Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeHundredTwentyFiveColumbiaParkwayMember" xlink:label="cli_ThreeHundredTwentyFiveColumbiaParkwayMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeHundredTwentyFiveColumbiaParkwayMember" xlink:to="cli_ThreeHundredTwentyFiveColumbiaParkwayMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeHundredTwentyFiveColumbiaParkwayMember_lbl" xml:lang="en-US">Three Hundred Twenty Five Columbia Parkway [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeHundredTwentyFiveColumbiaParkwayMember_lbl" xml:lang="en-US">Three Hundred Twenty Five Columbia Parkway [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeHundredTwentyFiveColumbiaParkwayMember_lbl" xml:lang="en-US">325 Columbia Parkway [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneGiraldaFarmsMember" xlink:label="cli_OneGiraldaFarmsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneGiraldaFarmsMember" xlink:to="cli_OneGiraldaFarmsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneGiraldaFarmsMember_lbl" xml:lang="en-US">One Giralda Farms [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneGiraldaFarmsMember_lbl" xml:lang="en-US">One Giralda Farms [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneGiraldaFarmsMember_lbl" xml:lang="en-US">1 Giralda Farms [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SevenGiraldaFarmsMember" xlink:label="cli_SevenGiraldaFarmsMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SevenGiraldaFarmsMember" xlink:to="cli_SevenGiraldaFarmsMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SevenGiraldaFarmsMember_lbl" xml:lang="en-US">Seven Giralda Farms [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SevenGiraldaFarmsMember_lbl" xml:lang="en-US">Seven Giralda Farms [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SevenGiraldaFarmsMember_lbl" xml:lang="en-US">7 Giralda Farms [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoHundredOneLittletonRoadMember" xlink:label="cli_TwoHundredOneLittletonRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoHundredOneLittletonRoadMember" xlink:to="cli_TwoHundredOneLittletonRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoHundredOneLittletonRoadMember_lbl" xml:lang="en-US">Two Hundred One Littleton Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoHundredOneLittletonRoadMember_lbl" xml:lang="en-US">Two Hundred One Littleton Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoHundredOneLittletonRoadMember_lbl" xml:lang="en-US">201 Littleton Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FourCampusDriveMember" xlink:label="cli_FourCampusDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FourCampusDriveMember" xlink:to="cli_FourCampusDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FourCampusDriveMember_lbl" xml:lang="en-US">Four Campus Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FourCampusDriveMember_lbl" xml:lang="en-US">Four Campus Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FourCampusDriveMember_lbl" xml:lang="en-US">4 Campus Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SixCampusDriveMember" xlink:label="cli_SixCampusDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SixCampusDriveMember" xlink:to="cli_SixCampusDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SixCampusDriveMember_lbl" xml:lang="en-US">Six Campus Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SixCampusDriveMember_lbl" xml:lang="en-US">Six Campus Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SixCampusDriveMember_lbl" xml:lang="en-US">6 Campus Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SevenCampusDriveMember" xlink:label="cli_SevenCampusDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SevenCampusDriveMember" xlink:to="cli_SevenCampusDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SevenCampusDriveMember_lbl" xml:lang="en-US">Seven Campus Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SevenCampusDriveMember_lbl" xml:lang="en-US">Seven Campus Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SevenCampusDriveMember_lbl" xml:lang="en-US">7 Campus Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EightCampusDriveMember" xlink:label="cli_EightCampusDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EightCampusDriveMember" xlink:to="cli_EightCampusDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EightCampusDriveMember_lbl" xml:lang="en-US">Eight Campus Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EightCampusDriveMember_lbl" xml:lang="en-US">Eight Campus Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_EightCampusDriveMember_lbl" xml:lang="en-US">8 Campus Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_NineCampusDriveMember" xlink:label="cli_NineCampusDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_NineCampusDriveMember" xlink:to="cli_NineCampusDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_NineCampusDriveMember_lbl" xml:lang="en-US">Nine Campus Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_NineCampusDriveMember_lbl" xml:lang="en-US">Nine Campus Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_NineCampusDriveMember_lbl" xml:lang="en-US">9 Campus Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoDrydenWayMember" xlink:label="cli_TwoDrydenWayMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoDrydenWayMember" xlink:to="cli_TwoDrydenWayMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoDrydenWayMember_lbl" xml:lang="en-US">Two Dryden Way [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoDrydenWayMember_lbl" xml:lang="en-US">Two Dryden Way [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoDrydenWayMember_lbl" xml:lang="en-US">2 Dryden Way [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FourGatehallDriveMember" xlink:label="cli_FourGatehallDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FourGatehallDriveMember" xlink:to="cli_FourGatehallDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FourGatehallDriveMember_lbl" xml:lang="en-US">Four Gatehall Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FourGatehallDriveMember_lbl" xml:lang="en-US">Four Gatehall Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FourGatehallDriveMember_lbl" xml:lang="en-US">4 Gatehall Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoHiltonCourtMember" xlink:label="cli_TwoHiltonCourtMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoHiltonCourtMember" xlink:to="cli_TwoHiltonCourtMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoHiltonCourtMember_lbl" xml:lang="en-US">Two Hilton Court [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoHiltonCourtMember_lbl" xml:lang="en-US">Two Hilton Court [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoHiltonCourtMember_lbl" xml:lang="en-US">2 Hilton Court [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneSylvanWayMember" xlink:label="cli_OneSylvanWayMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneSylvanWayMember" xlink:to="cli_OneSylvanWayMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneSylvanWayMember_lbl" xml:lang="en-US">One Sylvan Way [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneSylvanWayMember_lbl" xml:lang="en-US">One Sylvan Way [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneSylvanWayMember_lbl" xml:lang="en-US">1 Sylvan Way [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeSylvanWayMember" xlink:label="cli_ThreeSylvanWayMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeSylvanWayMember" xlink:to="cli_ThreeSylvanWayMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeSylvanWayMember_lbl" xml:lang="en-US">Three Sylvan Way [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeSylvanWayMember_lbl" xml:lang="en-US">Three Sylvan Way [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeSylvanWayMember_lbl" xml:lang="en-US">3 Sylvan Way [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FiveSylvanWayMember" xlink:label="cli_FiveSylvanWayMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FiveSylvanWayMember" xlink:to="cli_FiveSylvanWayMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiveSylvanWayMember_lbl" xml:lang="en-US">Five Sylvan Way [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiveSylvanWayMember_lbl" xml:lang="en-US">Five Sylvan Way [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiveSylvanWayMember_lbl" xml:lang="en-US">5 Sylvan Way [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SevenSylvanWayMember" xlink:label="cli_SevenSylvanWayMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SevenSylvanWayMember" xlink:to="cli_SevenSylvanWayMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SevenSylvanWayMember_lbl" xml:lang="en-US">Seven Sylvan Way [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SevenSylvanWayMember_lbl" xml:lang="en-US">Seven Sylvan Way [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SevenSylvanWayMember_lbl" xml:lang="en-US">7 Sylvan Way [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FiveWoodHollowRoadMember" xlink:label="cli_FiveWoodHollowRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FiveWoodHollowRoadMember" xlink:to="cli_FiveWoodHollowRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiveWoodHollowRoadMember_lbl" xml:lang="en-US">Five Wood Hollow Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiveWoodHollowRoadMember_lbl" xml:lang="en-US">Five Wood Hollow Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiveWoodHollowRoadMember_lbl" xml:lang="en-US">5 Wood Hollow Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SevenHundredTwentyOneRouteTwoHundredTwoSlashTwoHundredSixMember" xlink:label="cli_SevenHundredTwentyOneRouteTwoHundredTwoSlashTwoHundredSixMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SevenHundredTwentyOneRouteTwoHundredTwoSlashTwoHundredSixMember" xlink:to="cli_SevenHundredTwentyOneRouteTwoHundredTwoSlashTwoHundredSixMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SevenHundredTwentyOneRouteTwoHundredTwoSlashTwoHundredSixMember_lbl" xml:lang="en-US">Seven Hundred Twenty One Route Two Hundred Two Slash Two Hundred Six [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SevenHundredTwentyOneRouteTwoHundredTwoSlashTwoHundredSixMember_lbl" xml:lang="en-US">Seven Hundred Twenty One Route Two Hundred Two Slash Two Hundred Six [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SevenHundredTwentyOneRouteTwoHundredTwoSlashTwoHundredSixMember_lbl" xml:lang="en-US">721 Route 202/206 [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ElevenClearbrookRoadMember" xlink:label="cli_ElevenClearbrookRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ElevenClearbrookRoadMember" xlink:to="cli_ElevenClearbrookRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ElevenClearbrookRoadMember_lbl" xml:lang="en-US">Eleven Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ElevenClearbrookRoadMember_lbl" xml:lang="en-US">Eleven Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ElevenClearbrookRoadMember_lbl" xml:lang="en-US">11 Clearbrook Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SeventyFiveClearbrookRoadMember" xlink:label="cli_SeventyFiveClearbrookRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SeventyFiveClearbrookRoadMember" xlink:to="cli_SeventyFiveClearbrookRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SeventyFiveClearbrookRoadMember_lbl" xml:lang="en-US">Seventy Five Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SeventyFiveClearbrookRoadMember_lbl" xml:lang="en-US">Seventy Five Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SeventyFiveClearbrookRoadMember_lbl" xml:lang="en-US">75 Clearbrook Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredClearbrookRoadMember" xlink:label="cli_OneHundredClearbrookRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredClearbrookRoadMember" xlink:to="cli_OneHundredClearbrookRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredClearbrookRoadMember_lbl" xml:lang="en-US">One Hundred Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredClearbrookRoadMember_lbl" xml:lang="en-US">One Hundred Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredClearbrookRoadMember_lbl" xml:lang="en-US">100 Clearbrook Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredTwentyFiveClearbrookRoadMember" xlink:label="cli_OneHundredTwentyFiveClearbrookRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredTwentyFiveClearbrookRoadMember" xlink:to="cli_OneHundredTwentyFiveClearbrookRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredTwentyFiveClearbrookRoadMember_lbl" xml:lang="en-US">125 Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredTwentyFiveClearbrookRoadMember_lbl" xml:lang="en-US">One Hundred Twenty Five Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredTwentyFiveClearbrookRoadMember_lbl" xml:lang="en-US">125 Clearbrook Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredFiftyClearbrookRoadMember" xlink:label="cli_OneHundredFiftyClearbrookRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredFiftyClearbrookRoadMember" xlink:to="cli_OneHundredFiftyClearbrookRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredFiftyClearbrookRoadMember_lbl" xml:lang="en-US">150 Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredFiftyClearbrookRoadMember_lbl" xml:lang="en-US">One Hundred Fifty Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredFiftyClearbrookRoadMember_lbl" xml:lang="en-US">150 Clearbrook Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredSeventyFiveClearbrookRoadMember" xlink:label="cli_OneHundredSeventyFiveClearbrookRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredSeventyFiveClearbrookRoadMember" xlink:to="cli_OneHundredSeventyFiveClearbrookRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredSeventyFiveClearbrookRoadMember_lbl" xml:lang="en-US">175 Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredSeventyFiveClearbrookRoadMember_lbl" xml:lang="en-US">One Hundred Seventy Five Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredSeventyFiveClearbrookRoadMember_lbl" xml:lang="en-US">175 Clearbrook Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoHundredClearbrookRoadMember" xlink:label="cli_TwoHundredClearbrookRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoHundredClearbrookRoadMember" xlink:to="cli_TwoHundredClearbrookRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoHundredClearbrookRoadMember_lbl" xml:lang="en-US">Two Hundred Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoHundredClearbrookRoadMember_lbl" xml:lang="en-US">Two Hundred Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoHundredClearbrookRoadMember_lbl" xml:lang="en-US">200 Clearbrook Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoHundredFiftyClearbrookRoadMember" xlink:label="cli_TwoHundredFiftyClearbrookRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoHundredFiftyClearbrookRoadMember" xlink:to="cli_TwoHundredFiftyClearbrookRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoHundredFiftyClearbrookRoadMember_lbl" xml:lang="en-US">Two Hundred Fifty Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoHundredFiftyClearbrookRoadMember_lbl" xml:lang="en-US">Two Hundred Fifty Clearbrook Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoHundredFiftyClearbrookRoadMember_lbl" xml:lang="en-US">250 Clearbrook Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FiftyExecutiveBoulevardMember" xlink:label="cli_FiftyExecutiveBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FiftyExecutiveBoulevardMember" xlink:to="cli_FiftyExecutiveBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiftyExecutiveBoulevardMember_lbl" xml:lang="en-US">Fifty Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiftyExecutiveBoulevardMember_lbl" xml:lang="en-US">Fifty Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiftyExecutiveBoulevardMember_lbl" xml:lang="en-US">50 Executive Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SeventySevenExecutiveBoulevardMember" xlink:label="cli_SeventySevenExecutiveBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SeventySevenExecutiveBoulevardMember" xlink:to="cli_SeventySevenExecutiveBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SeventySevenExecutiveBoulevardMember_lbl" xml:lang="en-US">Seventy Seven Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SeventySevenExecutiveBoulevardMember_lbl" xml:lang="en-US">Seventy Seven Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SeventySevenExecutiveBoulevardMember_lbl" xml:lang="en-US">77 Executive Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EightyFiveExecutiveBoulevardMember" xlink:label="cli_EightyFiveExecutiveBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EightyFiveExecutiveBoulevardMember" xlink:to="cli_EightyFiveExecutiveBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EightyFiveExecutiveBoulevardMember_lbl" xml:lang="en-US">Eighty Five Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EightyFiveExecutiveBoulevardMember_lbl" xml:lang="en-US">Eighty Five Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_EightyFiveExecutiveBoulevardMember_lbl" xml:lang="en-US">85 Executive Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredOneExecutiveBoulevardMember" xlink:label="cli_OneHundredOneExecutiveBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredOneExecutiveBoulevardMember" xlink:to="cli_OneHundredOneExecutiveBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredOneExecutiveBoulevardMember_lbl" xml:lang="en-US">One Hundred One Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredOneExecutiveBoulevardMember_lbl" xml:lang="en-US">One Hundred One Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredOneExecutiveBoulevardMember_lbl" xml:lang="en-US">101 Executive Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeHundredExecutiveBoulevardMember" xlink:label="cli_ThreeHundredExecutiveBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeHundredExecutiveBoulevardMember" xlink:to="cli_ThreeHundredExecutiveBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeHundredExecutiveBoulevardMember_lbl" xml:lang="en-US">Three Hundred Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeHundredExecutiveBoulevardMember_lbl" xml:lang="en-US">Three Hundred Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeHundredExecutiveBoulevardMember_lbl" xml:lang="en-US">300 Executive Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeHundredFiftyExecutiveBoulevardMember" xlink:label="cli_ThreeHundredFiftyExecutiveBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeHundredFiftyExecutiveBoulevardMember" xlink:to="cli_ThreeHundredFiftyExecutiveBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeHundredFiftyExecutiveBoulevardMember_lbl" xml:lang="en-US">Three Hundred Fifty Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeHundredFiftyExecutiveBoulevardMember_lbl" xml:lang="en-US">Three Hundred Fifty Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeHundredFiftyExecutiveBoulevardMember_lbl" xml:lang="en-US">350 Executive Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeHundredNinetyNineExecutiveBoulevardMember" xlink:label="cli_ThreeHundredNinetyNineExecutiveBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeHundredNinetyNineExecutiveBoulevardMember" xlink:to="cli_ThreeHundredNinetyNineExecutiveBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeHundredNinetyNineExecutiveBoulevardMember_lbl" xml:lang="en-US">Three Hundred Ninety Nine Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeHundredNinetyNineExecutiveBoulevardMember_lbl" xml:lang="en-US">Three Hundred Ninety Nine Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeHundredNinetyNineExecutiveBoulevardMember_lbl" xml:lang="en-US">399 Executive Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FourHundredExecutiveBoulevardMember" xlink:label="cli_FourHundredExecutiveBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FourHundredExecutiveBoulevardMember" xlink:to="cli_FourHundredExecutiveBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FourHundredExecutiveBoulevardMember_lbl" xml:lang="en-US">Four Hundred Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FourHundredExecutiveBoulevardMember_lbl" xml:lang="en-US">Four Hundred Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FourHundredExecutiveBoulevardMember_lbl" xml:lang="en-US">400 Executive Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FiveHundredExecutiveBoulevardMember" xlink:label="cli_FiveHundredExecutiveBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FiveHundredExecutiveBoulevardMember" xlink:to="cli_FiveHundredExecutiveBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiveHundredExecutiveBoulevardMember_lbl" xml:lang="en-US">Five Hundred Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiveHundredExecutiveBoulevardMember_lbl" xml:lang="en-US">Five Hundred Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiveHundredExecutiveBoulevardMember_lbl" xml:lang="en-US">500 Executive Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FiveHundredTwentyFiveExecutiveBoulevardMember" xlink:label="cli_FiveHundredTwentyFiveExecutiveBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FiveHundredTwentyFiveExecutiveBoulevardMember" xlink:to="cli_FiveHundredTwentyFiveExecutiveBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiveHundredTwentyFiveExecutiveBoulevardMember_lbl" xml:lang="en-US">Five Hundred Twenty Five Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiveHundredTwentyFiveExecutiveBoulevardMember_lbl" xml:lang="en-US">Five Hundred Twenty Five Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiveHundredTwentyFiveExecutiveBoulevardMember_lbl" xml:lang="en-US">525 Executive Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneWarehouseLaneMember" xlink:label="cli_OneWarehouseLaneMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneWarehouseLaneMember" xlink:to="cli_OneWarehouseLaneMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneWarehouseLaneMember_lbl" xml:lang="en-US">One Warehouse Lane [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneWarehouseLaneMember_lbl" xml:lang="en-US">One Warehouse Lane [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneWarehouseLaneMember_lbl" xml:lang="en-US">1 Warehouse Lane [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoWarehouseLaneMember" xlink:label="cli_TwoWarehouseLaneMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoWarehouseLaneMember" xlink:to="cli_TwoWarehouseLaneMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoWarehouseLaneMember_lbl" xml:lang="en-US">Two Warehouse Lane [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoWarehouseLaneMember_lbl" xml:lang="en-US">Two Warehouse Lane [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoWarehouseLaneMember_lbl" xml:lang="en-US">2 Warehouse Lane [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeWarehouseLaneMember" xlink:label="cli_ThreeWarehouseLaneMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeWarehouseLaneMember" xlink:to="cli_ThreeWarehouseLaneMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeWarehouseLaneMember_lbl" xml:lang="en-US">Three Warehouse Lane [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeWarehouseLaneMember_lbl" xml:lang="en-US">Three Warehouse Lane [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeWarehouseLaneMember_lbl" xml:lang="en-US">3 Warehouse Lane [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FourWarehouseLaneMember" xlink:label="cli_FourWarehouseLaneMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FourWarehouseLaneMember" xlink:to="cli_FourWarehouseLaneMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FourWarehouseLaneMember_lbl" xml:lang="en-US">Four Warehouse Lane [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FourWarehouseLaneMember_lbl" xml:lang="en-US">Four Warehouse Lane [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FourWarehouseLaneMember_lbl" xml:lang="en-US">4 Warehouse Lane [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FiveWarehouseLaneMember" xlink:label="cli_FiveWarehouseLaneMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FiveWarehouseLaneMember" xlink:to="cli_FiveWarehouseLaneMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiveWarehouseLaneMember_lbl" xml:lang="en-US">Five Warehouse Lane [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiveWarehouseLaneMember_lbl" xml:lang="en-US">Five Warehouse Lane [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiveWarehouseLaneMember_lbl" xml:lang="en-US">5 Warehouse Lane [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SixWarehouseLaneMember" xlink:label="cli_SixWarehouseLaneMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SixWarehouseLaneMember" xlink:to="cli_SixWarehouseLaneMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SixWarehouseLaneMember_lbl" xml:lang="en-US">Six Warehouse Lane [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SixWarehouseLaneMember_lbl" xml:lang="en-US">Six Warehouse Lane [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SixWarehouseLaneMember_lbl" xml:lang="en-US">6 Warehouse Lane [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneWestchesterPlazaMember" xlink:label="cli_OneWestchesterPlazaMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneWestchesterPlazaMember" xlink:to="cli_OneWestchesterPlazaMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneWestchesterPlazaMember_lbl" xml:lang="en-US">One Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneWestchesterPlazaMember_lbl" xml:lang="en-US">One Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneWestchesterPlazaMember_lbl" xml:lang="en-US">1 Westchester Plaza [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoWestchesterPlazaMember" xlink:label="cli_TwoWestchesterPlazaMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoWestchesterPlazaMember" xlink:to="cli_TwoWestchesterPlazaMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoWestchesterPlazaMember_lbl" xml:lang="en-US">Two Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoWestchesterPlazaMember_lbl" xml:lang="en-US">Two Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoWestchesterPlazaMember_lbl" xml:lang="en-US">2 Westchester Plaza [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeWestchesterPlazaMember" xlink:label="cli_ThreeWestchesterPlazaMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeWestchesterPlazaMember" xlink:to="cli_ThreeWestchesterPlazaMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeWestchesterPlazaMember_lbl" xml:lang="en-US">Three Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeWestchesterPlazaMember_lbl" xml:lang="en-US">Three Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeWestchesterPlazaMember_lbl" xml:lang="en-US">3 Westchester Plaza [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FourWestchesterPlazaMember" xlink:label="cli_FourWestchesterPlazaMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FourWestchesterPlazaMember" xlink:to="cli_FourWestchesterPlazaMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FourWestchesterPlazaMember_lbl" xml:lang="en-US">Four Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FourWestchesterPlazaMember_lbl" xml:lang="en-US">Four Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FourWestchesterPlazaMember_lbl" xml:lang="en-US">4 Westchester Plaza [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FiveWestchesterPlazaMember" xlink:label="cli_FiveWestchesterPlazaMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FiveWestchesterPlazaMember" xlink:to="cli_FiveWestchesterPlazaMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiveWestchesterPlazaMember_lbl" xml:lang="en-US">Five Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiveWestchesterPlazaMember_lbl" xml:lang="en-US">Five Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiveWestchesterPlazaMember_lbl" xml:lang="en-US">5 Westchester Plaza [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SixWestchesterPlazaMember" xlink:label="cli_SixWestchesterPlazaMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SixWestchesterPlazaMember" xlink:to="cli_SixWestchesterPlazaMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SixWestchesterPlazaMember_lbl" xml:lang="en-US">Six Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SixWestchesterPlazaMember_lbl" xml:lang="en-US">Six Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SixWestchesterPlazaMember_lbl" xml:lang="en-US">6 Westchester Plaza [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SevenWestchesterPlazaMember" xlink:label="cli_SevenWestchesterPlazaMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SevenWestchesterPlazaMember" xlink:to="cli_SevenWestchesterPlazaMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SevenWestchesterPlazaMember_lbl" xml:lang="en-US">Seven Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SevenWestchesterPlazaMember_lbl" xml:lang="en-US">Seven Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SevenWestchesterPlazaMember_lbl" xml:lang="en-US">7 Westchester Plaza [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EightWestchesterPlazaMember" xlink:label="cli_EightWestchesterPlazaMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EightWestchesterPlazaMember" xlink:to="cli_EightWestchesterPlazaMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EightWestchesterPlazaMember_lbl" xml:lang="en-US">Eight Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EightWestchesterPlazaMember_lbl" xml:lang="en-US">Eight Westchester Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_EightWestchesterPlazaMember_lbl" xml:lang="en-US">8 Westchester Plaza [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoHundredSawMillRiverRoadMember" xlink:label="cli_TwoHundredSawMillRiverRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoHundredSawMillRiverRoadMember" xlink:to="cli_TwoHundredSawMillRiverRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoHundredSawMillRiverRoadMember_lbl" xml:lang="en-US">200 Saw Mill River Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoHundredSawMillRiverRoadMember_lbl" xml:lang="en-US">Two Hundred Saw Mill River Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoHundredSawMillRiverRoadMember_lbl" xml:lang="en-US">200 Saw Mill River Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneSkylineDriveMember" xlink:label="cli_OneSkylineDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneSkylineDriveMember" xlink:to="cli_OneSkylineDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneSkylineDriveMember_lbl" xml:lang="en-US">One Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneSkylineDriveMember_lbl" xml:lang="en-US">One Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneSkylineDriveMember_lbl" xml:lang="en-US">1 Skyline Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoSkylineDriveMember" xlink:label="cli_TwoSkylineDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoSkylineDriveMember" xlink:to="cli_TwoSkylineDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoSkylineDriveMember_lbl" xml:lang="en-US">Two Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoSkylineDriveMember_lbl" xml:lang="en-US">Two Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoSkylineDriveMember_lbl" xml:lang="en-US">2 Skyline Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FourSkylineDriveMember" xlink:label="cli_FourSkylineDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FourSkylineDriveMember" xlink:to="cli_FourSkylineDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FourSkylineDriveMember_lbl" xml:lang="en-US">Four Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FourSkylineDriveMember_lbl" xml:lang="en-US">Four Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FourSkylineDriveMember_lbl" xml:lang="en-US">4 Skyline Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FiveSkylineDriveMember" xlink:label="cli_FiveSkylineDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FiveSkylineDriveMember" xlink:to="cli_FiveSkylineDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiveSkylineDriveMember_lbl" xml:lang="en-US">Five Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiveSkylineDriveMember_lbl" xml:lang="en-US">Five Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiveSkylineDriveMember_lbl" xml:lang="en-US">5 Skyline Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SixSkylineDriveMember" xlink:label="cli_SixSkylineDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SixSkylineDriveMember" xlink:to="cli_SixSkylineDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SixSkylineDriveMember_lbl" xml:lang="en-US">Six Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SixSkylineDriveMember_lbl" xml:lang="en-US">Six Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SixSkylineDriveMember_lbl" xml:lang="en-US">6 Skyline Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SevenSkylineDriveMember" xlink:label="cli_SevenSkylineDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SevenSkylineDriveMember" xlink:to="cli_SevenSkylineDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SevenSkylineDriveMember_lbl" xml:lang="en-US">Seven Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SevenSkylineDriveMember_lbl" xml:lang="en-US">Seven Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SevenSkylineDriveMember_lbl" xml:lang="en-US">7 Skyline Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_EightSkylineDriveMember" xlink:label="cli_EightSkylineDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_EightSkylineDriveMember" xlink:to="cli_EightSkylineDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_EightSkylineDriveMember_lbl" xml:lang="en-US">Eight Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_EightSkylineDriveMember_lbl" xml:lang="en-US">Eight Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_EightSkylineDriveMember_lbl" xml:lang="en-US">8 Skyline Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TenSkylineDriveMember" xlink:label="cli_TenSkylineDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TenSkylineDriveMember" xlink:to="cli_TenSkylineDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TenSkylineDriveMember_lbl" xml:lang="en-US">Ten Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TenSkylineDriveMember_lbl" xml:lang="en-US">Ten Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TenSkylineDriveMember_lbl" xml:lang="en-US">10 Skyline Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ElevenSkylineDriveMember" xlink:label="cli_ElevenSkylineDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ElevenSkylineDriveMember" xlink:to="cli_ElevenSkylineDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ElevenSkylineDriveMember_lbl" xml:lang="en-US">Eleven Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ElevenSkylineDriveMember_lbl" xml:lang="en-US">Eleven Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ElevenSkylineDriveMember_lbl" xml:lang="en-US">11 Skyline Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwelveSkylineDriveMember" xlink:label="cli_TwelveSkylineDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwelveSkylineDriveMember" xlink:to="cli_TwelveSkylineDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwelveSkylineDriveMember_lbl" xml:lang="en-US">Twelve Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwelveSkylineDriveMember_lbl" xml:lang="en-US">Twelve Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwelveSkylineDriveMember_lbl" xml:lang="en-US">12 Skyline Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FifteenSkylineDriveMember" xlink:label="cli_FifteenSkylineDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FifteenSkylineDriveMember" xlink:to="cli_FifteenSkylineDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FifteenSkylineDriveMember_lbl" xml:lang="en-US">Fifteen Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FifteenSkylineDriveMember_lbl" xml:lang="en-US">Fifteen Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FifteenSkylineDriveMember_lbl" xml:lang="en-US">15 Skyline Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SeventeenSkylineDriveMember" xlink:label="cli_SeventeenSkylineDriveMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SeventeenSkylineDriveMember" xlink:to="cli_SeventeenSkylineDriveMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SeventeenSkylineDriveMember_lbl" xml:lang="en-US">Seventeen Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SeventeenSkylineDriveMember_lbl" xml:lang="en-US">Seventeen Skyline Drive [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SeventeenSkylineDriveMember_lbl" xml:lang="en-US">17 Skyline Drive [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoHundredThirtyWhitePlainsRoadMember" xlink:label="cli_TwoHundredThirtyWhitePlainsRoadMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoHundredThirtyWhitePlainsRoadMember" xlink:to="cli_TwoHundredThirtyWhitePlainsRoadMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoHundredThirtyWhitePlainsRoadMember_lbl" xml:lang="en-US">Two Hundred Thirty White Plains Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoHundredThirtyWhitePlainsRoadMember_lbl" xml:lang="en-US">Two Hundred Thirty White Plains Road [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoHundredThirtyWhitePlainsRoadMember_lbl" xml:lang="en-US">230 White Plains Road [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneBarkerAvenueMember" xlink:label="cli_OneBarkerAvenueMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneBarkerAvenueMember" xlink:to="cli_OneBarkerAvenueMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneBarkerAvenueMember_lbl" xml:lang="en-US">One Barker Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneBarkerAvenueMember_lbl" xml:lang="en-US">One Barker Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneBarkerAvenueMember_lbl" xml:lang="en-US">1 Barker Avenue [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeBarkerAvenueMember" xlink:label="cli_ThreeBarkerAvenueMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeBarkerAvenueMember" xlink:to="cli_ThreeBarkerAvenueMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeBarkerAvenueMember_lbl" xml:lang="en-US">Three Barker Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeBarkerAvenueMember_lbl" xml:lang="en-US">Three Barker Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeBarkerAvenueMember_lbl" xml:lang="en-US">3 Barker Avenue [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneHundredCorporateBoulevardMember" xlink:label="cli_OneHundredCorporateBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneHundredCorporateBoulevardMember" xlink:to="cli_OneHundredCorporateBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneHundredCorporateBoulevardMember_lbl" xml:lang="en-US">One Hundred Corporate Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneHundredCorporateBoulevardMember_lbl" xml:lang="en-US">One Hundred Corporate Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneHundredCorporateBoulevardMember_lbl" xml:lang="en-US">100 Corporate Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoHundredCorporateBoulevardSouthMember" xlink:label="cli_TwoHundredCorporateBoulevardSouthMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoHundredCorporateBoulevardSouthMember" xlink:to="cli_TwoHundredCorporateBoulevardSouthMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoHundredCorporateBoulevardSouthMember_lbl" xml:lang="en-US">Two Hundred Corporate Boulevard South [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoHundredCorporateBoulevardSouthMember_lbl" xml:lang="en-US">Two Hundred Corporate Boulevard South [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoHundredCorporateBoulevardSouthMember_lbl" xml:lang="en-US">200 Corporate Boulevard South [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneExecutiveBoulevardMember" xlink:label="cli_OneExecutiveBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneExecutiveBoulevardMember" xlink:to="cli_OneExecutiveBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneExecutiveBoulevardMember_lbl" xml:lang="en-US">One Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneExecutiveBoulevardMember_lbl" xml:lang="en-US">One Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneExecutiveBoulevardMember_lbl" xml:lang="en-US">1 Executive Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_TwoExecutiveBoulevardMember" xlink:label="cli_TwoExecutiveBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_TwoExecutiveBoulevardMember" xlink:to="cli_TwoExecutiveBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_TwoExecutiveBoulevardMember_lbl" xml:lang="en-US">Two Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_TwoExecutiveBoulevardMember_lbl" xml:lang="en-US">Two Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_TwoExecutiveBoulevardMember_lbl" xml:lang="en-US">2 Executive Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeExecutiveBoulevardMember" xlink:label="cli_ThreeExecutiveBoulevardMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeExecutiveBoulevardMember" xlink:to="cli_ThreeExecutiveBoulevardMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeExecutiveBoulevardMember_lbl" xml:lang="en-US">Three Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeExecutiveBoulevardMember_lbl" xml:lang="en-US">Three Executive Boulevard [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeExecutiveBoulevardMember_lbl" xml:lang="en-US">3 Executive Boulevard [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FourExecutivePlazaMember" xlink:label="cli_FourExecutivePlazaMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FourExecutivePlazaMember" xlink:to="cli_FourExecutivePlazaMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FourExecutivePlazaMember_lbl" xml:lang="en-US">Four Executive Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FourExecutivePlazaMember_lbl" xml:lang="en-US">Four Executive Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FourExecutivePlazaMember_lbl" xml:lang="en-US">4 Executive Plaza [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SixExecutivePlazaMember" xlink:label="cli_SixExecutivePlazaMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SixExecutivePlazaMember" xlink:to="cli_SixExecutivePlazaMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SixExecutivePlazaMember_lbl" xml:lang="en-US">Six Executive Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SixExecutivePlazaMember_lbl" xml:lang="en-US">Six Executive Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SixExecutivePlazaMember_lbl" xml:lang="en-US">6 Executive Plaza [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_OneOdellPlazaMember" xlink:label="cli_OneOdellPlazaMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_OneOdellPlazaMember" xlink:to="cli_OneOdellPlazaMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_OneOdellPlazaMember_lbl" xml:lang="en-US">One Odell Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_OneOdellPlazaMember_lbl" xml:lang="en-US">One Odell Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_OneOdellPlazaMember_lbl" xml:lang="en-US">1 Odell Plaza [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_ThreeOdellPlazaMember" xlink:label="cli_ThreeOdellPlazaMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_ThreeOdellPlazaMember" xlink:to="cli_ThreeOdellPlazaMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_ThreeOdellPlazaMember_lbl" xml:lang="en-US">Three Odell Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_ThreeOdellPlazaMember_lbl" xml:lang="en-US">Three Odell Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_ThreeOdellPlazaMember_lbl" xml:lang="en-US">3 Odell Plaza [Member]</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FiveOdellPlazaMember" xlink:to="cli_FiveOdellPlazaMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiveOdellPlazaMember_lbl" xml:lang="en-US">Five Odell Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiveOdellPlazaMember_lbl" xml:lang="en-US">Five Odell Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiveOdellPlazaMember_lbl" xml:lang="en-US">5 Odell Plaza [Member]</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SevenOdellPlazaMember" xlink:to="cli_SevenOdellPlazaMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SevenOdellPlazaMember_lbl" xml:lang="en-US">Seven Odell Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SevenOdellPlazaMember_lbl" xml:lang="en-US">Seven Odell Plaza [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SevenOdellPlazaMember_lbl" xml:lang="en-US">7 Odell Plaza [Member]</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FourHundredNineteenWestAvenueMember" xlink:to="cli_FourHundredNineteenWestAvenueMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FourHundredNineteenWestAvenueMember_lbl" xml:lang="en-US">Four Hundred Nineteen West Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FourHundredNineteenWestAvenueMember_lbl" xml:lang="en-US">Four Hundred Nineteen West Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FourHundredNineteenWestAvenueMember_lbl" xml:lang="en-US">419 West Avenue [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FiveHundredWestAvenueMember" xlink:label="cli_FiveHundredWestAvenueMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FiveHundredWestAvenueMember" xlink:to="cli_FiveHundredWestAvenueMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiveHundredWestAvenueMember_lbl" xml:lang="en-US">Five Hundred West Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiveHundredWestAvenueMember_lbl" xml:lang="en-US">Five Hundred West Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiveHundredWestAvenueMember_lbl" xml:lang="en-US">500 West Avenue [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_FiveHundredFiftyWestAvenueMember" xlink:label="cli_FiveHundredFiftyWestAvenueMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_FiveHundredFiftyWestAvenueMember" xlink:to="cli_FiveHundredFiftyWestAvenueMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_FiveHundredFiftyWestAvenueMember_lbl" xml:lang="en-US">Five Hundred Fifty West Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_FiveHundredFiftyWestAvenueMember_lbl" xml:lang="en-US">Five Hundred Fifty West Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_FiveHundredFiftyWestAvenueMember_lbl" xml:lang="en-US">550 West Avenue [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SixHundredWestAvenueMember" xlink:label="cli_SixHundredWestAvenueMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SixHundredWestAvenueMember" xlink:to="cli_SixHundredWestAvenueMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SixHundredWestAvenueMember_lbl" xml:lang="en-US">Six Hundred West Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SixHundredWestAvenueMember_lbl" xml:lang="en-US">Six Hundred West Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SixHundredWestAvenueMember_lbl" xml:lang="en-US">600 West Avenue [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_SixHundredFiftyWestAvenueMember" xlink:label="cli_SixHundredFiftyWestAvenueMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_SixHundredFiftyWestAvenueMember" xlink:to="cli_SixHundredFiftyWestAvenueMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_SixHundredFiftyWestAvenueMember_lbl" xml:lang="en-US">Six Hundred Fifty West Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_SixHundredFiftyWestAvenueMember_lbl" xml:lang="en-US">Six Hundred Fifty West Avenue [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_SixHundredFiftyWestAvenueMember_lbl" xml:lang="en-US">650 West Avenue [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_PortsideAtPierOneMember" xlink:label="cli_PortsideAtPierOneMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_PortsideAtPierOneMember" xlink:to="cli_PortsideAtPierOneMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_PortsideAtPierOneMember_lbl" xml:lang="en-US">Portside At Pier One [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_PortsideAtPierOneMember_lbl" xml:lang="en-US">Portside At Pier One [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_PortsideAtPierOneMember_lbl" xml:lang="en-US">Portside At Pier One [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AlterraAtOverlookRidgeIMember" xlink:label="cli_AlterraAtOverlookRidgeIMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AlterraAtOverlookRidgeIMember" xlink:to="cli_AlterraAtOverlookRidgeIMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AlterraAtOverlookRidgeIMember_lbl" xml:lang="en-US">Alterra At Overlook Ridge IA [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AlterraAtOverlookRidgeIMember_lbl" xml:lang="en-US">Alterra At Overlook Ridge I [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AlterraAtOverlookRidgeIMember_lbl" xml:lang="en-US">Alterra At Overlook Ridge IA [Member]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_AlterraAtOverlookRidgeIIMember" xlink:label="cli_AlterraAtOverlookRidgeIIMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_AlterraAtOverlookRidgeIIMember" xlink:to="cli_AlterraAtOverlookRidgeIIMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_AlterraAtOverlookRidgeIIMember_lbl" xml:lang="en-US">Alterra at Overlook Ridge II [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_AlterraAtOverlookRidgeIIMember_lbl" xml:lang="en-US">Alterra At Overlook Ridge I I [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_AlterraAtOverlookRidgeIIMember_lbl" xml:lang="en-US">Alterra at Overlook Ridge II [Member]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgageLoansOnRealEstateLoanTypeAxis" xlink:label="us-gaap_MortgageLoansOnRealEstateLoanTypeAxis" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MortgageLoansOnRealEstateLoanTypeAxis" xlink:to="us-gaap_MortgageLoansOnRealEstateLoanTypeAxis_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageLoansOnRealEstateLoanTypeAxis_lbl" xml:lang="en-US">Mortgage Loans on Real Estate, Loan Type [Axis]</label>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgageLoansOnRealEstateLoanTypeDomain" xlink:label="us-gaap_MortgageLoansOnRealEstateLoanTypeDomain" />
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageLoansOnRealEstateLoanTypeDomain_lbl" xml:lang="en-US">Mortgage Loans On Real Estate Loan Type [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MortgageLoansOnRealEstateLoanTypeDomain_lbl" xml:lang="en-US">Mortgage Loans on Real Estate, Loan Type [Domain]</label>
    <loc xlink:type="locator" xlink:href="cli-20171231.xsd#cli_BorrowerMember" xlink:label="cli_BorrowerMember" />
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cli_BorrowerMember" xlink:to="cli_BorrowerMember_lbl" />
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="cli_BorrowerMember_lbl" xml:lang="en-US">Borrower A [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="cli_BorrowerMember_lbl" xml:lang="en-US">Borrower [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="cli_BorrowerMember_lbl" xml:lang="en-US">Borrower A [Member]</label>
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