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Exhibit 4.1
 TENTH SUPPLEMENTAL INDENTURE
 RECITALS
 WHEREAS,
 WHEREAS,
 WHEREAS,
 WHEREAS,
 WHEREAS,
 NOW, THEREFORE IT IS AGREED:
 ARTICLE ONE
Definitions, Creation, Form and Terms and Conditions of the Debt Securities
 SECTION 1.01 Definitions
 Closing Date
 2




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Global Note
 Indenture
 Intercompany Debt
 Subsidiary
  Reinvestment Rate
 SECTION 1.02 Creation of the Debt Securities
  SECTION 1.03 Form of the Debt Securities
 3




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SECTION 1.04 Terms and Conditions of the Debt Securities
 Optional Redemption
    Maturity; Payment of Principal and Interest
 4




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Applicability of Defeasance or Covenant Defeasance
 ARTICLE TWO
Additional Covenants
       5




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ARTICLE THREE
Trustee
 SECTION 3.01 Trustee
 ARTICLE FOUR
Miscellaneous Provisions
 SECTION 4.01 Ratification of Original Indenture
 SECTION 4.02 Effect of Headings
 SECTION 4.03 Successors and Assigns
 SECTION 4.04 Separability Clause
 SECTION 4.05 Governing Law
 SECTION 4.06 Counterparts
 6




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IN WITNESS WHEREOF
 LIBERTY PROPERTY LIMITED PARTNERSHIPBy:
    
    Liberty Property Trust,as its sole General PartnerBy:
    
    /s/ William P. HankowskyName:
    
    William P. HankowskyTitle:
    
    President and Chief Executive Officer
 Attest:/s/ James J. BowesName:
    
    James J. BowesTitle:
    
    Secretary and General Counsel
 THE BANK OF NEW YORK TRUST COMPANY, N.A., as TrusteeBy:
    Sharon McGrathName:
    Sharon McGrathTitle:
    Vice President Attest:Janice Ott RotunnoName:
    
    Janice Ott RotunnoTitle:
    
    Vice President
 Supplemental Indenture




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THIS NOTE IS A GLOBAL SECURITY WITHIN THE MEANING OF THE INDENTURE HEREINAFTER REFERRED TO. UNLESS
THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A
NEW YORK CORPORATION (DTC), TO THE ISSUER OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR
PAYMENT AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS
IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO
SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC, ANY TRANSFER, PLEDGE, OR
OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED
OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.
 UNLESS AND UNTIL THIS CERTIFICATE IS EXCHANGED IN WHOLE OR IN PART FOR NOTES IN CERTIFICATED FORM,
THIS CERTIFICATE MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY DTC TO A NOMINEE THEREOF OR BY A
NOMINEE THEREOF TO DTC OR ANOTHER NOMINEE OF DTC OR BY DTC OR ANY SUCH NOMINEE TO A SUCCESSOR OF
DTC OR A NOMINEE OF SUCH SUCCESSOR.
 REGISTERED
    
    REGISTEREDNO.
    
    PRINCIPAL AMOUNTCUSIP NO. 53117C AL 6
    
    $
 LIBERTY PROPERTY LIMITED PARTNERSHIP
 6.625% Senior Note due 2017




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LIBERTY
PROPERTY LIMITED PARTNERSHIP,      as
IssuerBy:
    
    LIBERTY PROPERTY TRUST, as its sole General Partner
 By:Name:Title:By:Name:Title: Signature Page to Note




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TRUSTEES CERTIFICATE OF AUTHENTICATION
  THE BANK OF NEW YORK TRUST
COMPANY, N.A., as TrusteeBy:Authorized Signatory A-6




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LIBERTY PROPERTY LIMITED PARTNERSHIP
 6.625% Senior Note due 2017
     A-7




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A-8




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A-9




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