EIGHTH SUPPLEMENTAL INDENTURE, dated as of March 1, 2005, between
LIBERTY PROPERTY LIMITED PARTNERSHIP, a Pennsylvania limited partnership (the
"Company"), having its principal offices at 500 Chesterfield Parkway, Malvern,
Pennsylvania 19355, and J.P. MORGAN TRUST COMPANY, NATIONAL ASSOCIATION, a
national banking association organized under the laws of the United States of
America, as trustee (the "Trustee"), having its Corporate Trust Office at 227
West Monroe Street, Chicago, Illinois 60606.


                                    RECITALS

            WHEREAS, the Company executed and delivered its Indenture (the
"Original Indenture"), dated as of October 24, 1997, to the Trustee to issue
from time to time for its lawful purposes debt securities evidencing its
unsecured indebtedness.

            WHEREAS, the Original Indenture provides that by means of a
supplemental indenture, the Company may create one or more series of its debt
securities and establish the form and terms and conditions thereof.

            WHEREAS, the Company intends by this Eighth Supplemental Indenture
to (i) create a series of debt securities to be issued from time to time in an
unlimited principal amount entitled "Liberty Property Limited Partnership 5.125%
Senior Notes due 2015" (the "Notes"); and (ii) establish the forms and the terms
and conditions of such Notes.

            WHEREAS, the Board of Trustees of Liberty Property Trust (the
"Trust"), the general partner of the Company, has approved the creation of the
Notes and the form, terms and conditions thereof.

            WHEREAS, the consent of Holders to the execution and delivery of
this Eighth Supplemental Indenture is not required, and all other actions
required to be taken under the Original Indenture with respect to this Eighth
Supplemental Indenture have been taken.

            NOW, THEREFORE IT IS AGREED:


                                   ARTICLE ONE
  DEFINITIONS, CREATION, FORM AND TERMS AND CONDITIONS OF THE DEBT SECURITIES

      SECTION 1.01 DEFINITIONS. (a) Capitalized terms used in this Eighth
Supplemental Indenture and not otherwise defined shall have the meanings
ascribed to them in the Original Indenture. In addition, the following
additional terms shall have the following meanings to be equally applicable to
both the singular and the plural forms of the terms defined:

            "CLOSING DATE" means March 1, 2005.

            "GLOBAL NOTE" means a single fully-registered global note in book
entry form, without coupons, substantially in the form of Exhibit A attached
hereto.


                                       1

            "INDENTURE" means the Original Indenture as supplemented by this
Eighth Supplemental Indenture

            "INTERCOMPANY DEBT" means Debt to which the only parties are the
Trust, any of its subsidiaries, the Company and any Subsidiary, or Debt owed to
the Trust arising from routine cash management practices, but only so long as
such Debt is held solely by any of the Trust, any of its subsidiaries, the
Company and any Subsidiary.

            "SUBSIDIARY" shall have the meaning provided in the Original
Indenture and shall include Liberty Property Development Corp.-II.

      (b) The following term, which is defined in the Original Indenture, is
amended and restated as follows:

            "REINVESTMENT RATE" means the yield on Treasury securities at a
constant maturity corresponding to the remaining life (as of the date of
redemption, and rounded to the nearest month) to Stated Maturity of the
principal being redeemed (the "Treasury Yield"), plus 0.15%. For purposes
hereof, the Treasury Yield shall be equal to the arithmetic mean of the yields
published in the Statistical Release under the heading "Week Ending" for "U.S.
Government Securities - Treasury Constant Maturities" with a maturity equal to
such remaining life; provided, that if no published maturity exactly corresponds
to such remaining life, then the Treasury Yield shall be interpolated or
extrapolated on a straight-line basis from the arithmetic means of the yields
for the next shortest and next longest published maturities. For purposes of
calculating the Reinvestment Rate, the most recent Statistical Release published
prior to the date of determination of the Make-Whole Amount shall be used. If
the format or content of the Statistical Release changes in a manner that
precludes determination of the Treasury Yield in the above manner, then the
Treasury Yield shall be determined in the manner that most closely approximates
the above manner, as reasonably determined by the Company.

      SECTION 1.02 CREATION OF THE DEBT SECURITIES. In accordance with Section
301 of the Original Indenture, the Company hereby creates the Notes as a
separate series of its debt securities issued pursuant to the Indenture. The
Notes shall be issued in an aggregate principal amount initially limited to
$300,000,000.

      The Company may issue, in addition to the Notes originally issued on the
Closing Date, additional Notes. The Notes originally issued on the Closing Date
and any additional Notes originally issued subsequent to the Closing Date shall
be a single series for all purposes under the Indenture.

      SECTION 1.03 FORM OF THE DEBT SECURITIES. The Notes will be represented by
one or more fully-registered global notes in book-entry form, without coupons,
registered in the name of the nominee of DTC. The Notes shall be in the form of
Exhibit A attached hereto. So long as DTC, or its nominee, is the registered
owner of a Global Note, DTC or its nominee, as the case may be, will be
considered the sole owner or holder of the Notes represented by such Global Note
for all purposes under the Indenture. Ownership of beneficial interests in the
Global Note will be shown on, and transfers thereof will be effected only
through, records maintained by

                                       2

DTC (with respect to beneficial interests of participants) or by participants or
persons that hold interests through participants (with respect to beneficial
interests of beneficial owners).

      SECTION 1.04 TERMS AND CONDITIONS OF THE DEBT SECURITIES. The Notes shall
be governed by all the terms and conditions of the Original Indenture, as
supplemented by this Eighth Supplemental Indenture, and in particular, the
following provisions shall be the terms of the Notes:

      (a) Optional Redemption. The Issuer may redeem the Notes at any time at
the option of the Issuer, in whole or from time to time in part, at a redemption
price equal to the Redemption Price.

      If notice of redemption has been given as provided in the Indenture and
funds for the redemption of any Notes called for redemption shall have been made
available on the Redemption Date referred to in such notice, such Notes will
cease to bear interest on the date fixed for such redemption specified in such
notice and the only right of the Holders of such Notes from and after the
Redemption Date will be to receive payment of the Redemption Price upon
surrender of such Notes in accordance with such notice.

      Notice of any optional redemption of any Notes will be given to Holders at
their addresses, as shown in the security register for the Notes, not more than
60 nor less than 30 days prior to the date fixed for redemption. The notice of
redemption will specify, among other items, the Redemption Price and the
principal amount of the Notes held by such Holder to be redeemed.

      If all or less than all of the Notes are to be redeemed at the option of
the Issuer, the Issuer will notify the Trustee at least 45 days prior to giving
notice of redemption (or such shorter period as is satisfactory to the Trustee)
of the aggregate principal amount of Notes to be redeemed, if less than all of
the Notes are to be redeemed, and their Redemption Date. The Trustee shall
select, in such manner as it shall deem fair and appropriate, no less than 60
days prior to the date of redemption, the Notes to be redeemed in whole or in
part.

      (b) Maturity; Payment of Principal and Interest. The principal amount of
the Notes shall be payable on March 2, 2015, subject to the provisions of the
Indenture and the Notes. Interest will accrue from March 1, 2005. The Notes will
bear interest at 5.125% per annum, payable in the manner and on the dates set
forth in the Notes. Principal and interest payments on interests represented by
a Global Note will be made to DTC or its nominee, as the case may be, as the
registered owner of such Global Note. All payments of principal and interest in
respect of the Notes will be made by the Issuer in immediately available funds.
The principal of this Note payable on the Maturity Date will be paid against
presentation and surrender of this Note at the corporate trust office of the
Trustee at 227 West Monroe Street, Chicago, Illinois 60606, in such coin or
currency of the United States of America as at the time of payment is legal
tender for payment of public or private debt.

      (c) Applicability of Defeasance or Covenant Defeasance. The provisions of
Article 14 of the Original Indenture shall apply to the Notes.


                                       3

                                   ARTICLE TWO
                              ADDITIONAL COVENANTS

      The Notes shall be governed by all the covenants contained in the Original
Indenture, as supplemented by this Eighth Supplemental Indenture. In addition,
this Eighth Supplemental Indenture amends and restates Section 1004 of the
Original Indenture to read as follows:

      "SECTION 1004. Limitations on Incurrence of Debt.

      (a) The Company will not, and will not permit any Subsidiary to, incur any
Debt, other than Intercompany Debt, that is subordinate in right of payment to
the Notes, if, immediately after giving effect to the incurrence of such Debt
and the application of the proceeds thereof, the aggregate principal amount of
all outstanding Debt of the Company and its Subsidiaries on a consolidated basis
determined in accordance with GAAP is greater than 60% of the sum of (i) the
Company's Adjusted Total Assets as of the end of the most recent fiscal quarter
prior to the incurrence of such additional Debt and (ii) the increase in
Adjusted Total Assets since the end of such quarter (including any increase
resulting from the incurrence of additional Debt).

      (b) The Company will not, and will not permit any Subsidiary to, incur any
Debt if the ratio of Consolidated Income Available for Debt Service to the
Annual Service Charge on the date on which such additional Debt is to be
incurred, on a pro forma basis, after giving effect to the incurrence of such
Debt and to the application of the proceeds thereof would have been less than
1.5 to 1.

      (c) The Company will not, and will not permit any Subsidiary to, incur any
Debt secured by any mortgage, lien, charge, pledge, encumbrance or security
interest of any kind upon any of the properties of the Company or any Subsidiary
("Secured Debt"), whether owned at the date hereof or hereafter acquired, if,
immediately after giving effect to the incurrence of such Secured Debt and the
application of the proceeds thereof, the aggregate principal amount of all
outstanding Secured Debt of the Company and its Subsidiaries on a consolidated
basis is greater than 40% of the sum of (i) the Company's Adjusted Total Assets
as of the end of the most recent fiscal quarter prior to the incurrence of such
additional Debt and (ii) the increase in Adjusted Total Assets since the end of
such quarter (including any increase resulting from the incurrence of additional
Debt).

      (d) The Company will at all time maintain an Unencumbered Total Asset
Value in an amount not less than 150% of the aggregate principal amount of all
outstanding unsecured Debt of the Company and its Subsidiaries on a consolidated
basis.

            For purposes of the foregoing provisions regarding the limitation on
the incurrence of Debt, Debt shall be deemed to be "incurred" by the Company or
a Subsidiary whenever the Company or such Subsidiary shall create, assume,
guarantee or otherwise become liable in respect thereof."


                                       4

                                  ARTICLE THREE
                                     TRUSTEE

      SECTION 3.01 TRUSTEE. The Trustee shall not be responsible in any manner
whatsoever for or in respect of the validity or sufficiency of this Eighth
Supplemental Indenture or the due execution thereof by the Company. The recitals
of fact contained herein shall be taken as the statements solely of the Company,
and the Trustee assumes no responsibility for the correctness thereof.

                                  ARTICLE FOUR
                            MISCELLANEOUS PROVISIONS

      SECTION 4.01 RATIFICATION OF ORIGINAL INDENTURE. This Eighth Supplemental
Indenture is executed and shall be construed as an indenture supplemental to the
Original Indenture, and as supplemented and modified hereby, the Original
Indenture is in all respects ratified and confirmed, and the Original Indenture
and this Eighth Supplemental Indenture shall be read, taken and construed as one
and the same instrument.

      SECTION 4.02 EFFECT OF HEADINGS. The Article and Section headings herein
are for convenience only and shall not affect the construction hereof.

      SECTION 4.03 SUCCESSORS AND ASSIGNS. All covenants and agreements in this
Eighth Supplemental Indenture by the Company shall bind its successors and
assigns, whether so expressed or not.

      SECTION 4.04 SEPARABILITY CLAUSE. In case any one or more of the
provisions contained in this Eighth Supplemental Indenture shall for any reason
be held to be invalid, illegal or unenforceable in any respect, the validity,
legality and enforceability of the remaining provisions shall not in any way be
affected or impaired thereby.

      SECTION 4.05 GOVERNING LAW. This Eighth Supplemental Indenture shall be
governed by and construed in accordance with the laws of the State of New York.
This Eighth Supplemental Indenture is subject to the provisions of the Trust
Indenture Act, that are required to be part of this Eighth Supplemental
Indenture and shall, to the extent applicable, be governed by such provisions.

      SECTION 4.06 COUNTERPARTS. This Eighth Supplemental Indenture may be
executed in any number of counterparts, and each of such counterparts shall for
all purposes be deemed to be an original, but all such counterparts shall
together constitute one and the same instrument.


                                       5

      IN WITNESS WHEREOF, the parties hereto have caused this Eighth
Supplemental Indenture to be duly executed, and their respective corporate seals
to be hereunto affixed and attested, all as of the date first above written.



                                    LIBERTY PROPERTY LIMITED PARTNERSHIP

                                    By:   Liberty Property Trust,
                                          as its sole General Partner


                                    By: /s/ William P. Hankowsky
                                        --------------------------------------
                                        Name:  William P. Hankowsky
                                        Title: President and Chief
                                               Executive Officer


Attest:

/s/ James J. Bowes
- ---------------------------
Name:  James J. Bowes
Title: Secretary


                                    J.P. MORGAN TRUST COMPANY,
                                    NATIONAL ASSOCIATION
                                        as Trustee


                                    By: /s/ Renee Johnson
                                        --------------------------------------
                                        Name:  Renee Johnson
                                        Title: Vice President

Attest:

/s/ Janice Ott Rotunno
- ----- ----------------------
Name:  Janice Ott Rotunno
Title: Assistant Vice President


                                       6

                                                                       Exhibit A
                                 [FACE OF NOTE]

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                                                            REGISTERED

NO. 1                                                           PRINCIPAL AMOUNT

CUSIP NO. 53117C AJ 1
                                                                    $300,000,000


                      LIBERTY PROPERTY LIMITED PARTNERSHIP

                          5.125% SENIOR NOTES DUE 2015

            Liberty Property Limited Partnership, a Pennsylvania limited
partnership (the "Issuer," which term includes any successor under the Indenture
hereinafter referred to), for value received, hereby promises to pay to Cede &
Co. or its registered assigns, the principal sum of 300,000,000 Dollars on March
2, 2015 (the "Maturity Date"), and to pay interest thereon from March 1, 2005
(or from the most recent interest payment date to which interest has been paid
or duly provided for), semi-annually in arrears on June 1 and December 1 of each
year (each, an "Interest Payment Date"), commencing on June 1, 2005, and on the
Maturity Date, at the rate of 5.125% per annum, until payment of said principal
sum has been made or duly provided for.

            The interest so payable and punctually paid or duly provided for on
any Interest Payment Date and on the Maturity Date will be paid to the Holder in
whose name this Note (or

                                       A-1

one or more predecessor Notes) is registered at the close of business on the
"Record Date" for such payment, which will be 15 days (regardless of whether
such day is a Business Day (as defined below)) prior to such payment date or the
Maturity Date, as the case may be. Any interest not so punctually paid or duly
provided for shall forthwith cease to be payable to the Holder on such record
date, and shall be paid to the Holder in whose name this Note (or one or more
predecessor Notes) is registered at the close of business on a subsequent record
date for the payment of such defaulted interest (which shall be not more than 15
days and not less than 10 days prior to the date of the payment of such
defaulted interest) established by notice given by mail by or on behalf of the
Issuer to the Holders of the Notes not less than 10 days preceding such
subsequent record date. Interest on this Note will be computed on the basis of a
360-day year of twelve 30-day months.

            The principal of this Note payable on the Maturity Date will be paid
against presentation and surrender of this Note at the corporate trust office of
the Trustee at 227 West Monroe Street, Chicago, Illinois 60606, in such coin or
currency of the United States of America as at the time of payment is legal
tender for payment of public or private debt.

            Interest payable on this Note on any Interest Payment Date and on
the Maturity Date, as the case may be, will be the amount of interest accrued
from and including the immediately preceding Interest Payment Date (or from and
including March 1, 2005, in the case of the initial Interest Payment Date) to
but excluding the applicable Interest Payment Date or the Maturity Date, as the
case may be. If any Interest Payment Date or the Maturity Date falls on a day
that is not a Business Day (as defined below), the required payment of interest
or principal or both, as the case may be, will be made on the next Business Day
with the same force and effect as if it were made on the date such payment was
due and no interest will accrue on the amount so payable for the period from and
after such Interest Payment Date or the Maturity Date, as the case may be.
"Business Day" means any day, other than a Saturday or a Sunday, that is neither
a legal holiday nor a day on which banking institutions in The City of New York
or Chicago are authorized or required by law, regulation or executive order to
close.

            Payments of principal and interest in respect of this Note will be
made by wire transfer of immediately available funds in such coin or currency of
the United States of America as at the time of payment is legal tender for the
payment of public and private debts.

            Reference is made to the further provisions of this Note set forth
on the reverse hereof. Such further provisions shall for all purposes have the
same effect as though fully set forth at this place.

            This Note shall not be entitled to the benefits of the Indenture
referred to on the reverse hereof or be valid or become obligatory for any
purpose until the certificate of authentication hereon shall have been signed by
the Trustee under such Indenture.


                                      A-2

            IN WITNESS WHEREOF, the Issuer has caused this instrument to be
signed manually or by facsimile by its authorized officers.


Dated: March 1, 2005



                              LIBERTY PROPERTY LIMITED PARTNERSHIP,
                                    as Issuer

                              By:   LIBERTY PROPERTY TRUST,
                                       as its sole General Partner


                              By:_____________________________________________
                                   Name:
                                   Title:



                              By:_____________________________________________
                                   Name:
                                   Title:


                                      A-3

                     TRUSTEE'S CERTIFICATE OF AUTHENTICATION



            This is one of the Securities of the series designated herein
referred to in the within-mentioned Indenture.



                              J.P. MORGAN TRUST COMPANY,
                              NATIONAL ASSOCIATION
                                   as Trustee



                              By:_____________________________________________
                                    Authorized Officer


                                      A-4

                                [REVERSE OF NOTE]

                      LIBERTY PROPERTY LIMITED PARTNERSHIP

                          5.125% SENIOR NOTES DUE 2015


            This security is one of a duly authorized issue of debentures,
notes, bonds, or other evidences of indebtedness of the Issuer (hereinafter
called the "Securities") of the series hereinafter specified, all issued or to
be issued under and pursuant to an Indenture dated as of October 24, 1997
(herein called the "Indenture"), duly executed and delivered by the Issuer to
J.P. Morgan Trust Company, National Association (as successor to the First
National Bank of Chicago), as Trustee (herein called the "Trustee," which term
includes any successor trustee under the Indenture with respect to the series of
Securities of which this Note is a part), to which Indenture and all indentures
supplemental thereto relating to this security reference is hereby made for a
description of the rights, limitations of rights, obligations, duties, and
immunities thereunder of the Trustee, the Issuer, and the Holders of the
Securities, and of the terms upon which the Securities are, and are to be,
authenticated and delivered. The Securities may be issued in one or more series,
which different series may be issued in various aggregate principal amounts, may
mature at different times, may bear interest (if any) at different rates, may be
subject to different redemption provisions (if any), and may otherwise vary as
provided in the Indenture or any indenture supplemental thereto. This security
is one of a series designated as the 5.125% Notes due 2015 of the Issuer.

            In case an Event of Default with respect to this security shall have
occurred and be continuing, the principal hereof and Make-Whole Amount, if any,
may be declared, and upon such declaration shall become, due and payable, in the
manner, with the effect, and subject to the conditions provided in the
Indenture.

            The Issuer may redeem this security at any time at the option of the
Issuer, in whole or from time to time in part, at a redemption price equal to
the sum of (i) the principal amount of this security being redeemed plus accrued
interest thereon to the Redemption Date and (ii) the Make-Whole Amount, if any,
with respect to this security. Notice of any optional redemption of any
Securities will be given to Holders at their addresses, as shown in the security
register for the Securities, not more than 60 nor less than 30 days prior to the
date fixed for redemption. The notice of redemption will specify, among other
items, the Redemption Price and the principal amount of the Securities held by
such Holder to be redeemed.

            The Indenture contains provisions permitting the Issuer and the
Trustee, with the consent of the Holders of not less than a majority of the
aggregate principal amount of the Securities at the time Outstanding of all
series to be affected (voting as one class), evidenced as provided in the
Indenture, to execute supplemental indentures adding any provisions to or
changing in any manner or eliminating any of the provisions of the Indenture or
of any supplemental indenture or modifying in any manner the rights of the
Holders of the Securities of each series; provided, however, that no such
supplemental indenture shall, without the consent of the Holder of each Security
so affected, (i) change the Stated Maturity of the principal of (or

                                      A-5

premium or Make-Whole Amount, if any, on) or any installment of interest on, any
such Security, (ii) reduce the principal amount of, or the rate or amount of
interest on, or any premium payable on redemption of the Notes, or adversely
affect any right of repayment of the Holder of any Securities; (iii) change the
place of payment, or the coin or currency, for payment of principal or premium,
if any, or interest on the Securities; (iv) impair the right to institute suit
for the enforcement of any payment on or with respect to the Securities on or
after the stated maturity of any such Security; (v) reduce the above-stated
percentage in principal amount of outstanding Securities, the extent of whose
Holders is necessary to modify or amend the Indenture, for any waiver with
respect to the Securities or to waive compliance with certain provisions of the
Indenture or certain defaults and consequences thereunder or to reduce the
quorum or voting requirements set forth in the Indenture; or (vi) modify any of
the foregoing provisions or any of the provisions relating to the waiver of
certain past defaults or certain covenants, except to increase the required
percentage to effect such action or to provide that certain other provisions of
the Indenture may not be modified or waived without the consent of the Holder of
each Security. It is also provided in the Indenture that, with respect to
certain defaults or Events of Default regarding the Securities of any series,
the Holders of a majority in aggregate principal amount outstanding of the
Securities of such series (or, in the case of certain defaults or Events of
Default, all series of Securities) may on behalf of the Holders of all the
Securities of such series (or all of the Securities, as the case may be) waive
any such past default or Event of Default and its consequences, prior to any
declaration accelerating the maturity of such Securities, or, subject to certain
conditions, may rescind a declaration of acceleration and its consequences with
respect to such Securities. Any such consent or waiver by the Holder of this
Security (unless revoked as provided in the Indenture) shall be conclusive and
binding upon such Holder and upon all future Holders and owners of this Security
and any Securities that may be issued in exchange or substitution herefor,
irrespective of whether or not any notation thereof is made upon this security
or such other securities.

            No reference herein to the Indenture and no provision of this
security or of the Indenture shall alter or impair the obligation of the Issuer,
which is absolute and unconditional, to pay the principal of and any Make-Whole
Amount and interest on this security in the manner, at the respective times, at
the rate and in the coin or currency herein prescribed.

            This security is issuable only in registered form without coupons in
denominations of $1,000 and integral multiples thereof. Securities may be
exchanged for a like aggregate principal amount of securities of this series of
other authorized denominations at the office or agency of the Issuer in The
Borough of Manhattan, The City of New York, in the manner and subject to the
limitations provided in the Indenture, but without the payment of any service
charge except for any tax or other governmental charge imposed in connection
therewith.

            Upon due presentment for registration of transfer of Securities at
the office or agency of the Issuer in The Borough of Manhattan, The City of New
York, one or more new Securities of the same series of authorized denominations
in an equal aggregate principal amount will be issued to the transferee in
exchange therefor, subject to the limitations provided in the Indenture, without
charge except for any tax or other governmental charge imposed in connection
therewith.

            The Issuer, the Trustee or any authorized agent of the Issuer or the
Trustee may

                                      A-6

deem and treat the Person in whose name this security is registered as the
absolute owner of this security (whether or not this security shall be overdue
and notwithstanding any notation of ownership or other writing hereon), for the
purpose of receiving payment of, or on account of, the principal hereof and
Make-Whole Amount, if any, and subject to the provisions on the face hereof,
interest hereon, and for all other purposes, and neither the Issuer nor the
Trustee nor any authorized agent of the Issuer or the Trustee shall be affected
by any notice to the contrary.

            The Indenture and each Security shall be deemed to be a contract
under the laws of the State of New York, and for all purposes shall be construed
in accordance with the laws of such state, except as may otherwise be required
by mandatory provisions of law.

            Capitalized terms used herein which are not otherwise defined shall
have the respective meanings assigned to them in the Indenture and all
indentures supplemental thereto relating to this Security.


                                      A-7

- --------------------------------------------------------------------------------

                      LIBERTY PROPERTY LIMITED PARTNERSHIP
                                     ISSUER

                                       TO

                 J.P. MORGAN TRUST COMPANY, NATIONAL ASSOCIATION
                                     TRUSTEE


                             -----------------------

                          EIGHTH SUPPLEMENTAL INDENTURE

                            DATED AS OF MARCH 1, 2005

                             -----------------------


                          5.125% SENIOR NOTES DUE 2015

                             -----------------------


                          SUPPLEMENT TO INDENTURE,
                      DATED AS OF OCTOBER 24, 1997, BETWEEN
                    LIBERTY PROPERTY LIMITED PARTNERSHIP AND
                 J.P. MORGAN TRUST COMPANY, NATIONAL ASSOCIATION
              (AS SUCCESSOR TO THE FIRST NATIONAL BANK OF CHICAGO)

- --------------------------------------------------------------------------------