Document:

<PAGE>

                                                                     EXHIBIT 4.1

                                     Form of

                          SUPPLEMENTAL INDENTURE NO. 12

                                 by and between

                              HRPT PROPERTIES TRUST

                                       and

                         U.S. BANK NATIONAL ASSOCIATION

                             as of January 30, 2003

             SUPPLEMENTAL TO THE INDENTURE DATED AS OF JULY 9, 1997

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

                              HRPT PROPERTIES TRUST

                    6.40% Senior Notes due February 15, 2015

<PAGE>

         This SUPPLEMENTAL INDENTURE NO. 12 (this "Supplemental Indenture") made
and entered into as of January 30, 2003 between HRPT PROPERTIES TRUST, a
Maryland real estate investment trust (the "Company"), and U.S. BANK NATIONAL
ASSOCIATION, a national banking association (and successor to State Street Bank
and Trust Company ("State Street") in its capacity as Trustee), as Trustee (the
"Trustee"),

                                WITNESSETH THAT:

         WHEREAS, the Company and the Trustee have executed and delivered an
Indenture, dated as of July 9, 1997 (the "Indenture"), relating to the Company's
issuance, from time to time, of various series of debt securities; and

         WHEREAS, U.S. Bank National Association has acquired and succeeded to
substantially all of the corporate trust business of State Street, and, being
eligible to serve as trustee under the Indenture, has succeeded to State Street
as Trustee under the Indenture; and

         WHEREAS, the Company has determined to issue debt securities known as
its 6.40% Senior Notes due February 15, 2015; and

         WHEREAS, the Indenture provides that certain terms and conditions for
each series of debt securities issued by the Company thereunder may be set forth
in an indenture supplemental to the Indenture;

         NOW, THEREFORE, THIS SUPPLEMENTAL INDENTURE WITNESSETH:

                                   ARTICLE 1

                                  DEFINED TERMS

         SECTION 1.1 The following definitions supplement, and, to the extent
inconsistent with, replace the definitions in Section 101 of the Indenture:

         "Acquired Debt" means Debt of a Person or entity (i) existing at the
time such Person or entity becomes a Subsidiary or (ii) assumed in connection
with the acquisition of assets from such Person or entity, in each case, other
than Debt incurred in connection with, or in contemplation of, such Person or
entity becoming a Subsidiary or such acquisition. Acquired Debt shall be deemed
to be incurred on the date of the related acquisition of assets from any Person
or entity or the date the acquired Person or entity becomes a Subsidiary.

         "Annual Debt Service" as of any date means the maximum amount which is
expensed in any 12-month period for interest on Debt of the Company and its
Subsidiaries.

         "Business Day" means any day other than a Saturday or Sunday or a day
on which banking institutions in the City of New York or in the city in which
the Corporate Trust Office of the Trustee is located, are required or authorized
to close.

         "Capital Stock" means, with respect to any Person, any capital stock
(including preferred stock), shares, interests, participation or other ownership
interests (however designated) of such

<PAGE>

Person and any rights (other than debt securities convertible into or
exchangeable for capital stock), warrants or options to purchase any thereof.

         "Consolidated Income Available for Debt Service" for any period means
Earnings from Operations of the Company and its Subsidiaries plus amounts which
have been deducted, and minus amounts which have been added, for the following
(without duplication): (i) interest on Debt of the Company and its Subsidiaries,
(ii) provision for taxes of the Company and its Subsidiaries based on income,
(iii) amortization of debt discount and deferred financing costs, (iv)
provisions for gains and losses on properties and property, depreciation and
amortization, (v) the effect of any noncash charge resulting from a change in
accounting principles in determining Earnings from Operations for such period
and (vi) amortization of deferred charges.

         "Debt" of the Company or any Subsidiary means, without duplication, any
indebtedness of the Company or any Subsidiary, whether or not contingent, in
respect of (i) borrowed money or evidenced by bonds, notes, debentures or
similar instruments, (ii) indebtedness for borrowed money secured by any
Encumbrance existing on property owned by the Company or any Subsidiary, to the
extent of the lesser of (x) the amount of indebtedness so secured and (y) the
fair market value of the property subject to such Encumbrance, (iii) the
reimbursement obligations, contingent or otherwise, in connection with any
letters of credit actually issued (other than letters of credit issued to
provide credit enhancement or support with respect to other indebtedness of the
Company or any Subsidiary otherwise reflected as Debt hereunder) or amounts
representing the balance deferred and unpaid of the purchase price of any
property or services, except any such balance that constitutes an accrued
expense or trade payable, or all conditional sale obligations or obligations
under any title retention agreement, (iv) the principal amount of all
obligations of the Company or any Subsidiary with respect to redemption,
repayment or other repurchase of any Disqualified Stock, or (v) any lease of
property by the Company or any Subsidiary as lessee which is reflected on the
Company's consolidated balance sheet as a capitalized lease in accordance with
GAAP, to the extent, in the case of items of indebtedness under (i) through
(iii) above, that any such items (other than letters of credit) would appear as
a liability on the Company's consolidated balance sheet in accordance with GAAP,
and also includes, to the extent not otherwise included, any obligation by the
Company or any Subsidiary to be liable for, or to pay, as obligor, guarantor or
otherwise (other than for purposes of collection in the ordinary course of
business), Debt of another Person (other than the Company or any Subsidiary) (it
being understood that Debt shall be deemed to be incurred by the Company or any
Subsidiary whenever the Company or such Subsidiary shall create, assume,
guarantee or otherwise become liable in respect thereof).

         "Disqualified Stock" means, with respect to any Person, any Capital
Stock of such Person which by the terms of such Capital Stock (or by the terms
of any security into which it is convertible or for which it is exchangeable or
exercisable), upon the happening of any event or otherwise (i) matures or is
mandatorily redeemable, pursuant to a sinking fund obligation or otherwise
(other than Capital Stock which is redeemable solely in exchange for common
stock or shares), (ii) is convertible into or exchangeable or exercisable for
Debt or Disqualified Stock, or (iii) is redeemable at the option of the holder
thereof, in whole or in part (other than Capital Stock which is redeemable
solely in exchange for common stock or shares), in each case on or prior to the
stated maturity of the Notes.

                                      -2-

<PAGE>

         "Earnings from Operations" for any period means net earnings excluding
gains and losses on sales of investments, extraordinary items, gains and losses
on early extinguishment of debt and property valuation losses, as reflected in
the financial statements of the Company and its Subsidiaries for such period,
determined on a consolidated basis in accordance with GAAP.

         "Encumbrance" means any mortgage, lien, charge, pledge or security
interest of any kind.

         "Make-Whole Amount" means, in connection with any optional redemption
or accelerated payment of any notes prior to August 15, 2014, the excess, if
any, of (i) the aggregate present value as of the date of such redemption or
accelerated payment of each dollar of principal being redeemed or paid and the
amount of interest (exclusive of interest accrued to the date of redemption or
accelerated payment) that would have been payable in respect of such dollar if
such redemption or accelerated payment had been made on August 15, 2014,
determined by discounting, on a semiannual basis, such principal and interest at
the Reinvestment Rate (determined on the third Business Day preceding the date
such notice of redemption is given or declaration of acceleration is made) from
the respective dates on which such principal and interest would have been
payable if such redemption or accelerated payment had been made on August 15,
2014, over (ii) the aggregate principal amount of the Notes being redeemed or
paid. In the case of any redemption or accelerated payment of notes on or after
August 15, 2014, the Make-Whole Amount means zero. For purposes of this
Supplemental Indenture and the Notes, references in the Indenture to the payment
of the principal (and premium, if any) and interest on the Notes shall be deemed
to include the payment of the Make-Whole Amount, if any, due upon redemption
with respect to the Notes. The Make-Whole Amount shall be calculated by the
Company and set forth in an Officer's Certificate delivered to the Trustee, and
the Trustee shall be entitled to rely on said Officer's Certificate.

         "Notes" means the Company's 6.40% Senior Notes due February 15, 2015,
issued under this Supplemental Indenture and the Indenture, as amended or
supplemented from time to time.

         "Reinvestment Rate" means a rate per annum equal to the sum of 0.50%
(fifty one-hundredths of one percent) plus the yield on treasury securities at
constant maturity under the heading "Week Ending" published in the Statistical
Release under the caption "Treasury Constant Maturities" for the maturity
(rounded to the nearest month) corresponding to the remaining life to maturity
(which, in the case of maturities corresponding to the principal and interest
due on the notes at their maturity, shall be deemed to be August 15, 2014), as
of the payment date of the principal being redeemed or paid. If no maturity
exactly corresponds to such maturity, yields for the two published maturities
most closely corresponding to such maturity shall be calculated pursuant to the
immediately preceding sentence and the Reinvestment Rate shall be interpolated
or extrapolated from such yields on a straight-line basis, rounding in each of
such relevant periods to the nearest month. 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.

         "Secured Debt" means Debt secured by any mortgage, lien, charge, pledge
or security interest of any kind.

         "Statistical Release" means the statistical release designated
"H.15(519)" or any successor publication which is published weekly by the
Federal Reserve System and which establishes yields

                                      -3-

<PAGE>

on actively traded United States government securities adjusted to constant
maturities or, if such statistical release is not published at the time of any
determination under this Supplemental Indenture, then any publicly available
source of similar market data which shall be designated by the Company.

         "Subsidiary" means any corporation or other entity of which a majority
of (i) the voting power of the voting equity securities or (ii) the outstanding
equity interests of which are owned, directly or indirectly, by the Company or
one or more other Subsidiaries of the Company. For the purposes of this
definition, "voting equity securities" means equity securities having voting
power for the election of directors, whether at all times or only so long as no
senior class of security has such voting power by reason of any contingency.

         "Total Assets" as of any date means the sum of (i) the Undepreciated
Real Estate Assets and (ii) all other assets of the Company and its Subsidiaries
determined in accordance with GAAP (but excluding accounts receivable and
intangibles).

         "Total Unencumbered Assets" means the sum of (i) those Undepreciated
Real Estate Assets not subject to an Encumbrance for borrowed money and (ii) all
other assets of the Company and its Subsidiaries not subject to an Encumbrance
for borrowed money determined in accordance with GAAP (but excluding accounts
receivable and intangibles).

         "Undepreciated Real Estate Assets" as of any date means the cost
(original cost plus capital improvements) of real estate assets of the Company
and its Subsidiaries on such date, before depreciation and amortization,
determined on a consolidated basis in accordance with GAAP.

         "Unsecured Debt" means Debt which is not secured by any of the
properties of the Company or any Subsidiary.

                                   ARTICLE 2

                               TERMS OF THE NOTES

         SECTION 2.1 Pursuant to Section 301 of the Indenture, the Notes shall
have the following terms and conditions:

         (a) TITLE; AGGREGATE PRINCIPAL AMOUNT; FORM OF NOTES. The Notes shall
be Registered Securities under the Indenture and shall be known as the Company's
"6.40% Senior Notes due February 15, 2015." The Notes will be limited to an
aggregate principal amount of $200,000,000, subject to the right of the Company
to reopen such series for issuances of additional securities of such series and
except as provided in this Section and in Section 306 of the Indenture. The
Notes (together with the Trustee's certificate of authentication) shall be
substantially in the form of Exhibit A hereto, which is hereby incorporated in
and made a part of this Supplemental Indenture.

         The Notes will be issued in the form of one or more registered global
securities without coupons ("Global Notes") that will be deposited with, or on
behalf of, The Depository Trust Company ("DTC"), and registered in the name of
DTC's nominee, Cede & Co. Except under the circumstance described below, the
Notes will not be issuable in definitive form. Unless and until it is exchanged
in whole or in part for the individual notes represented thereby, a Global Note
may

                                      -4-

<PAGE>

not be transferred except as a whole by DTC to a nominee of DTC or by a nominee
of DTC to DTC or another nominee of DTC or by DTC or any nominee of DTC to a
successor depositary or any nominee of such successor.

         So long as DTC or its nominee is the registered owner of a Global Note,
DTC or such 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 this
Supplemental Indenture. Except as described below, owners of beneficial interest
in Notes evidenced by a Global Note will not be entitled to have any of the
individual Notes represented by such Global Note registered in their names, will
not receive or be entitled to receive physical delivery of any such Notes in
definitive form and will not be considered the owners or holders thereof under
the Indenture or this Supplemental Indenture.

         If DTC is at any time unwilling, unable or ineligible to continue as
depositary and a successor depositary is not appointed by the Company within 90
days, the Company will issue individual Notes in exchange for the Global Note or
Global Notes representing such Notes. In addition, the Company may at any time
and in its sole discretion, subject to certain limitations set forth in the
Indenture, determine not to have any of such Notes represented by one or more
Global Notes and, in such event, will issue individual Notes in exchange for the
Global Note or Global Notes representing the Notes. Individual Notes so issued
will be issued in denominations of $1,000 and integral multiples thereof.

         (b) INTEREST AND INTEREST RATE. The Notes will bear interest at a rate
of 6.40% per annum, from January 30, 2003 (or, in the case of Notes issued upon
the reopening of this series of Notes, from the date designated by the Company
in connection with such reopening) or from the immediately preceding Interest
Payment Date to which interest has been paid or duly provided for, payable
semiannually on each February 15 and August 15, commencing August 15, 2003 (each
of which shall be an "Interest Payment Date"), to the Persons in whose names the
Notes are registered in the Security Register at the close of business on the
day falling 14 calendar days (whether or not a Business Day) next preceding such
Interest Payment Date (each, a "Regular Record Date").

         (c) PRINCIPAL REPAYMENT; CURRENCY. The stated maturity of the Notes is
February 15, 2015, provided, however, the Notes may be earlier redeemed at the
option of the Company as provided in paragraph (d) below. The principal of each
Note payable on its maturity date shall be paid against presentation and
surrender thereof at the Corporate Trust Office of the Trustee, located
initially at Two Avenue de Lafayette, Boston, Massachusetts 02111, 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 or private debts. The Company will not pay
Additional Amounts (as defined in the Indenture) on the Notes.

         (d) REDEMPTION AT THE OPTION OF THE COMPANY; ACCELERATION. The Notes
will be subject to redemption at any time at the option of the Company, in whole
or in part, upon not less than 30 nor more than 60 days' notice to each Holder
of Notes to be redeemed at its address appearing in the Security Register, at a
price equal to the sum of (i) the principal amount of the Notes being redeemed,
plus accrued and unpaid interest to but excluding the applicable Redemption
Date, plus (ii) the Make-Whole Amount, if any. If the notes are redeemed on or
after August 15, 2014, the redemption price will not include the Make-Whole
Amount. Upon the acceleration of the Notes in

                                      -5-

<PAGE>

accordance with Section 502 of the Indenture, if such acceleration occurs prior
to August 15, 2014, the principal amount of the Notes, plus accrued and unpaid
interest thereon and the Make-Whole Amount shall become due and payable
immediately.

         (e) NOTICES. All notices and other communications hereunder shall be in
writing and shall be deemed to have been duly given if mailed or transmitted by
any standard form of telecommunication. Notices to the Company shall be directed
to it at 400 Centre Street, Newton, Massachusetts 02458, Attention: President;
notices to the Trustee shall be directed to it at Two Avenue de Lafayette,
Boston, Massachusetts 02111, Attention: Corporate Trust Department, Re: HRPT
Properties Trust 6.40% Senior Notes due February 15, 2015; or as to either
party, at such other address as shall be designated by such party in a written
notice to the other party.

         (f) GLOBAL NOTE LEGEND. Each Global Note shall bear the following
legend on the face thereof:

         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.

         (g) APPLICABILITY OF DISCHARGE, DEFEASANCE AND COVENANT DEFEASANCE
PROVISIONS. The Discharge, Defeasance and Covenant Defeasance provisions in
Article Fourteen of the Indenture will apply to the Notes.

                                   ARTICLE 3

                              ADDITIONAL COVENANTS

         SECTION 3.1 In addition to the covenants of the Company set forth in
Article Ten of the Indenture, for the benefit of the holders of the Notes:

         (a) LIMITATIONS ON INCURRENCE OF DEBT.

               (i) The Company will not, and will not permit any Subsidiary to,
          incur any Debt if, immediately after giving effect to the incurrence
          of such additional 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 ("Adjusted Total Assets") of
          (without duplication) (A) the Total Assets of the Company and its
          Subsidiaries as of the end of the calendar

                                      -6-

<PAGE>

          quarter covered in the Company's Annual Report on Form 10-K, or the
          Quarterly Report on Form 10-Q, as the case may be, most recently filed
          with the Securities and Exchange Commission (or, if such filing is not
          permitted under the Securities Exchange Act of 1934, as amended, with
          the Trustee) prior to the incurrence of such additional Debt and (B)
          the purchase price of any real estate assets or mortgages receivable
          acquired, and the amount of any securities offering proceeds received
          (to the extent that such proceeds were not used to acquire real estate
          assets or mortgages receivable or used to reduce Debt), by the Company
          or any Subsidiary since the end of such calendar quarter, including
          those proceeds obtained in connection with the incurrence of such
          additional Debt.

               (ii) In addition to the foregoing limitations on the incurrence
          of Debt, the Company will not, and will not permit any Subsidiary to,
          incur any Secured Debt if, immediately after giving effect to the
          incurrence of such additional 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 Adjusted Total Assets.

               (iii) In addition to the foregoing limitations on the incurrence
          of Debt, 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 Debt Service for the four consecutive fiscal
          quarters most recently ended prior to the date on which such
          additional Debt is to be incurred shall have been less than 1.5 to
          1.0, on a pro forma basis after giving effect thereto and to the
          application of the proceeds therefrom, and calculated on the
          assumption that (A) such Debt and any other Debt incurred by the
          Company and its Subsidiaries since the first day of such four-quarter
          period and the application of the proceeds therefrom, including to
          refinance other Debt, had occurred at the beginning of such period;
          (B) the repayment or retirement of any other Debt by the Company and
          its Subsidiaries since the first date of such four-quarter period had
          been repaid or retired at the beginning of such period (except that,
          in making such computation, the amount of Debt under any revolving
          credit facility shall be computed based upon the average daily balance
          of such Debt during such period); (C) in the case of Acquired Debt or
          Debt incurred in connection with any acquisition since the first day
          of such four-quarter period, the related acquisition had occurred as
          of the first day of such period with appropriate adjustments with
          respect to such acquisition being included in such pro forma
          calculation; and (D) in the case of any acquisition or disposition by
          the Company or its Subsidiaries of any asset or group of assets since
          the first day of such four-quarter period, whether by merger, stock
          purchase or sale, or asset purchase or sale, such acquisition or
          disposition or any related repayment of Debt had occurred as of the
          first day of such period with the appropriate adjustments with respect
          to such acquisition or disposition being included in such pro forma
          calculation. If the Debt giving rise to the need to make the foregoing
          calculation or any other Debt incurred after the first day of the
          relevant four-quarter period bears interest at a floating rate then,
          for purposes of calculating the Annual Debt Service, the interest rate
          on such Debt shall be computed on a pro forma basis as if the average
          interest rate which would have been in effect during the entire such
          four-quarter period had been the applicable rate for the entire such
          period.

                                      -7-

<PAGE>

         (b) MAINTENANCE OF TOTAL UNENCUMBERED ASSETS. The Company and its
Subsidiaries will maintain at all times Total Unencumbered Assets of not less
than 200% of the aggregate outstanding principal amount of the Unsecured Debt of
the Company and its Subsidiaries on a consolidated basis.

                                   ARTICLE 4

                          ADDITIONAL EVENTS OF DEFAULT

         SECTION 4.1 For purposes of this Supplemental Indenture and the Notes,
in addition to the Events of Default set forth in Section 501 of the Indenture,
it shall also constitute an "Event of Default" if a default under any bond,
debenture, note or other evidence of indebtedness of the Company (including a
default with respect to any other series of securities), or under any mortgage,
indenture or other instrument of the Company under which there may be issued or
by which there may be secured or evidenced any indebtedness for money borrowed
by the Company (or by any Subsidiary, the repayment of which the Company has
guaranteed or for which the Company is directly responsible or liable as obligor
or guarantor) having an aggregate principal amount outstanding of at least
$20,000,000, whether such indebtedness now exists or shall hereafter be incurred
or created, which default shall have resulted in such indebtedness becoming or
being declared due and payable prior to the date on which it would otherwise
have become due and payable, without such indebtedness having been discharged,
or such acceleration having been rescinded or annulled, within a period of ten
days after there shall have been given, by registered or certified mail, to the
Company by the Trustee or to the Company and the Trustee by the Holders of at
least 25% in principal amount of the outstanding Notes, a written notice
specifying such default and requiring the Company to cause such indebtedness to
be discharged or cause such acceleration to be rescinded or annulled and stating
that such notice is a "Notice of Default" hereunder.

         SECTION 4.2 Notwithstanding any provisions to the contrary in the
Indenture, upon any acceleration of the Notes under Section 502 of the
Indenture, the amount immediately due and payable in respect of the Notes shall
equal the Outstanding principal amount thereof, plus accrued interest, plus, if
such acceleration occurs prior to August 15, 2014, the Make-Whole Amount.

                                   ARTICLE 5

                                  EFFECTIVENESS

         This Supplemental Indenture shall be effective for all purposes as of
the date and time this Supplemental Indenture has been executed and delivered by
the Company and the Trustee in accordance with Article Nine of the Indenture. As
supplemented hereby, the Indenture is hereby confirmed as being in full force
and effect.

                                      -8-

<PAGE>

                                   ARTICLE 6

                                  MISCELLANEOUS

         SECTION 6.1 In the event any provision of this Supplemental Indenture
shall be held invalid or unenforceable by any court of competent jurisdiction,
such holding shall not invalidate or render unenforceable any other provision
hereof or any provision of the Indenture.

         SECTION 6.2 To the extent that any terms of this Supplemental Indenture
or the Notes are inconsistent with the terms of the Indenture, the terms of this
Supplemental Indenture or the Notes shall govern and supersede such inconsistent
terms.

         SECTION 6.3 This Supplemental Indenture shall be governed by and
construed in accordance with the laws of The Commonwealth of Massachusetts.

         SECTION 6.4 This Supplemental Indenture may be executed in several
counterparts, each of which shall be an original and all of which shall
constitute but one and the same instrument.

                  [Remainder of page intentionally left blank.]

                                      -9-

<PAGE>

         IN WITNESS WHEREOF, the Company and the Trustee have caused this
Supplemental Indenture to be executed as an instrument under seal in their
respective corporate names as of the date first above written.

                             HRPT PROPERTIES TRUST

                             By:
                                ------------------------------------------------
                                  Name:  John C. Popeo
                                  Title: Treasurer and Chief Financial Officer

                             U.S. BANK NATIONAL ASSOCIATION,
                             as Trustee

                             By:
                                ------------------------------------------------
                                  Name:
                                  Title:

                                      -10-

<PAGE>

                                                                       EXHIBIT A

                                  FORM OF NOTE

                                 [FACE OF NOTE]

                     6.40% Senior Note due February 15, 2015

No. ______                                                           $__________

                              HRPT PROPERTIES TRUST

promises to pay to _______ or registered assigns, the principal sum of
__________ ($_______) on January 15, 2013, subject to the terms set forth on the
reverse of this Note and the terms of the Indenture referred to therein.

         Interest Payment Dates: each February 15 and August 15, commencing
August 15, 2003.

         Record Dates: the day falling 14 calendar days prior to any Interest
Payment Date.

CUSIP No.:
           ------------------------

                                                      HRPT PROPERTIES TRUST

                                                      By:
                                                         -----------------------
                                                         Name:
                                                         Title:

Attest:
       ----------------------------
[SEAL]

CERTIFICATE OF AUTHENTICATION

Dated: January 30, 2003

This is one of the Notes referred to in the within-mentioned Indenture:

U.S. BANK NATIONAL ASSOCIATION, as Trustee

By:_______________________________
     Authorized Officer

<PAGE>

             [THE FOLLOWING CONSTITUTES THE REVERSE OF THE SECURITY]

                              HRPT PROPERTIES TRUST

                     6.40% Senior Note due February 15, 2015

         Capitalized terms used herein have the meanings assigned to them in the
Indenture (as defined below) unless otherwise indicated.

         1. INTEREST. HRPT Properties Trust, a Maryland real estate investment
trust (the "Company"), promises to pay interest on the principal amount of this
Note at the rate and in the manner specified below.

         The Company shall pay in cash interest on the principal amount of this
Note at the rate per annum of 6.40%. The Company will pay interest semi-annually
in arrears on each February 15 and August 15, commencing on August 15, 2003, or,
if any such day is not a Business Day (as defined in the Indenture), on the next
succeeding Business Day (each an "Interest Payment Date"), to Holders of record
on the day falling 14 calendar days immediately preceding such Interest Payment
Date (whether or not a Business Day).

         Interest will be computed on the basis of a 360-day year consisting of
twelve 30-day months. Interest shall accrue from the most recent date to which
interest has been paid or, if no interest has been paid, from January 30, 2003.

         2. METHOD OF PAYMENT. The Company will pay interest on the Notes
(except defaulted interest) to the Persons who are registered Holders of Notes
at the close of business on the record date next preceding the Interest Payment
Date, even if such Notes are canceled after such record date and on or before
such Interest Payment Date. The Company will pay principal and interest in money
of the United States that at the time of payment is legal tender for payment of
public and private debts. The Company, however, may pay principal, premium, if
any, and interest by check payable in such money. It may mail an interest check
to a Holder's registered address.

         3. INDENTURE. The Company issued the Notes under an Indenture, dated as
of July 9, 1997, and a Supplemental Indenture No. 12 thereto, dated as of
January 30, 2003 (collectively, the "Indenture"), between the Company and the
Trustee. The terms of the Notes include those stated in the Indenture and those
made part of the Indenture by reference to the Trust Indenture Act of 1939 as in
effect on the date of the Indenture. The Notes are subject to all such terms,
and Holders of the Notes are referred to the Indenture and such Act for a
statement of such terms. The terms of the Indenture shall govern any
inconsistencies between the Indenture and the Notes. The Notes are unsecured
general obligations of the Company limited to $200,000,000 in aggregate
principal amount, except as otherwise provided in the Indenture.

         4. OPTIONAL REDEMPTION. The Notes will be subject to redemption at any
time at the option of the Company, in whole or in part, upon not less than 30
nor more than 60 days' notice, at a redemption price equal to the sum of (i) the
principal amount of the Notes being redeemed, plus accrued and unpaid interest
to but excluding the applicable Redemption Date and (ii) the Make-Whole Amount,
if any. If the Notes are redeemed on or after August 15, 2014, the redemption
price will not include the Make-Whole Amount.

                                      A-2

<PAGE>

         As used herein the term "Make-Whole Amount" means, in connection with
any optional redemption or accelerated payment of any notes prior to August 15,
2014, the excess, if any, of (i) the aggregate present value as of the date of
such redemption or accelerated payment of each dollar of principal being
redeemed or paid and the amount of interest (exclusive of interest accrued to
the date of redemption or accelerated payment) that would have been payable in
respect of such dollar if such redemption or accelerated payment had been made
on August 15, 2014, determined by discounting, on a semiannual basis, such
principal and interest at the Reinvestment Rate (determined on the third
Business Day preceding the date such notice of redemption is given or
declaration of acceleration is made) from the respective dates on which such
principal and interest would have been payable if such redemption or accelerated
payment had been made on August 15, 2014, over (ii) the aggregate principal
amount of the Notes being redeemed or paid. In the case of any redemption or
accelerated payment of notes on or after August 15, 2014, the Make-Whole Amount
means zero. For purposes of the Indenture and the Notes, references in the
Indenture to the payment of the principal (and premium, if any) and interest on
the Notes shall be deemed to include the payment of the Make-Whole Amount, if
any, due upon redemption with respect to the Notes. The Make-Whole Amount shall
be calculated by the Company and set forth in an Officer's Certificate delivered
to the Trustee, and the Trustee shall be entitled to rely on said Officer's
Certificate.

         As used herein the term "Reinvestment Rate" means a rate per annum
equal to the sum of 0.50% (fifty one-hundredths of one percent) plus the yield
on treasury securities at constant maturity under the heading "Week Ending"
published in the Statistical Release (as defined herein) under the caption
"Treasury Constant Maturities" for the maturity (rounded to the nearest month)
corresponding to the remaining life to maturity (which, in the case of
maturities corresponding to the principal and interest due on the notes at their
maturity, shall be deemed to be August 15, 2014), as of the payment date of the
principal being redeemed or paid. If no maturity exactly corresponds to such
maturity, yields for the two published maturities most closely corresponding to
such maturity shall be calculated pursuant to the immediately preceding sentence
and the Reinvestment Rate shall be interpolated or extrapolated from such yields
on a straight-line basis, rounding in each of such relevant periods to the
nearest month. 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.

         As used herein the term "Statistical Release" means the statistical
release designated "H.15(519)" or any successor publication which is published
weekly by the Federal Reserve System and which establishes yields on actively
traded United States government securities adjusted to constant maturities or,
if such statistical release is not published at the time of any determination
under the Supplemental Indenture, then any publicly available source of similar
market data which shall be designated by the Company.

         5. MANDATORY REDEMPTION. The Company shall not be required to make
sinking fund or redemption payments with respect to the Notes.

         6. NOTICE OF REDEMPTION. Notice of redemption shall be mailed at least
30 days but not more than 60 days before the Redemption Date to each Holder of
Notes to be redeemed at its registered address. Notes may be redeemed in part
but only in whole multiples of $1,000, unless

                                      A-3

<PAGE>

all of the Notes held by a Holder are to be redeemed. On and after the
redemption date, interest ceases to accrue on Notes or portions of them called
for redemption.

         7. DENOMINATIONS, TRANSFER, EXCHANGE. The Notes are in registered form
without coupons in denominations of $1,000 and integral multiples of $1,000 in
excess thereof. The transfer of Notes may be registered and Notes may be
exchanged as provided in the Indenture. The Security Registrar and the Trustee
may require a Holder, among other things, to furnish appropriate endorsements
and transfer documents and to pay any taxes and fees required by law or
permitted by the Indenture. The Security Registrar need not exchange or register
the transfer of any Note or portion of a Note selected for redemption. Also, it
need not exchange or register the transfer of any Notes for a period of 15 days
before the mailing of a notice of redemption of Notes, or during the period
between a record date and the corresponding Interest Payment Date.

         8. DEFAULTS AND REMEDIES. In case an Event of Default (as defined in
the Indenture) with respect to the Notes shall have occurred and be continuing,
the principal hereof may be declared, and upon such declaration shall become,
due and payable, in the manner, with the effect and subject to the provisions
provided in the Indenture.

         9. ACTIONS OF HOLDERS. The Indenture contains provisions permitting the
holders of not less than a majority of the aggregate principal amount of the
outstanding Notes, subject to certain exceptions as provided in the Indenture,
on behalf of the holders of all such Notes at a meeting duly called and held as
provided in the Indenture, to make, give or take any request, demand,
authorization, direction, notice, consent, waiver or other action provided in
the Indenture to be made, given or taken by the holders of the Notes, including
without limitation, waiving (a) compliance by the Company with certain
provisions of the Indenture, and (b) certain past defaults under the Indenture
and their consequences. Any resolution passed or decision taken at any meeting
of the holders of the Notes in accordance with the provisions of the Indenture
shall be conclusive and binding upon such holders and upon all future holders of
this Note and other Notes issued upon the registration of transfer hereof or in
exchange heretofore or in lieu hereof.

         10. PERSONS DEEMED OWNERS. The Company, the Trustee, and any agent of
the Company or the Trustee may deem and treat the Person in whose name this Note
is registered on the Security Register as its absolute owner for all purposes.

         11. AUTHENTICATION. This Note shall not be valid until authenticated by
the manual signature of the Trustee or an authenticating agent.

         12. GOVERNING LAW. THE INTERNAL LAW OF THE COMMONWEALTH OF
MASSACHUSETTS SHALL GOVERN AND BE USED TO CONSTRUE THE INDENTURE AND THE NOTES.

         13. NO PERSONAL LIABILITY. THE AMENDED AND RESTATED DECLARATION OF
TRUST OF THE COMPANY, DATED JULY 1, 1994, A COPY OF WHICH, TOGETHER WITH ALL
AMENDMENTS THERETO (THE "DECLARATION"), IS DULY FILED IN THE OFFICE OF THE
DEPARTMENT OF ASSESSMENTS AND TAXATION OF THE STATE OF MARYLAND, PROVIDES THAT
THE NAME "HRPT PROPERTIES TRUST" REFERS TO THE TRUSTEES UNDER THE DECLARATION
COLLECTIVELY AS TRUSTEES, BUT NOT

                                      A-4

<PAGE>

INDIVIDUALLY OR PERSONALLY, AND THAT NO TRUSTEE, OFFICER, SHAREHOLDER, EMPLOYEE
OR AGENT OF THE COMPANY SHALL BE HELD TO ANY PERSONAL LIABILITY, JOINTLY OR
SEVERALLY, FOR ANY OBLIGATION OF, OR CLAIM AGAINST, THE COMPANY. ALL PERSONS
DEALING WITH THE COMPANY, IN ANY WAY, SHALL LOOK ONLY TO THE ASSETS OF THE
COMPANY FOR THE PAYMENT OF ANY SUM OR THE PERFORMANCE OF ANY OBLIGATION.

         The Company will furnish to any Holder upon written request and without
charge a copy of the Indenture. Request may be made to:

         HRPT Properties Trust
         400 Centre Street
         Newton, MA 02458
         Telecopier No.:  (617) 332-2261
         Attention: President

or such other address as the Company may specify pursuant to the Indenture.

                                      A-5

<PAGE>

                                 ASSIGNMENT FORM

                                   To assign this Note, fill in the form below:

[I] [We] assign and transfer this Note to ______________________________________

__________________________________ [PRINT OR TYPE ASSIGNEE'S NAME, ADDRESS AND
                                   ZIP CODE]

__________________________________ [INSERT ASSIGNEE'S SOC. SEC. OR TAX I.D. NO.]

and irrevocably appoint_________________________________________________________

to transfer this Note on the books of the Company. The agent may substitute

another to act for him.

Date:
      ----------------
                                   Your Signature:
                                                  ------------------------------
                                   [SIGN EXACTLY AS YOUR NAME APPEARS ON THE
                                   FACE OF THIS NOTE]

Signature Guarantee:

--------------------------
[THE SIGNATURE MUST BE GUARANTEED BY
AN OFFICER OF A PARTICIPANT IN A RECOGNIZED
SIGNATURE GUARANTEE PROGRAM. NOTARIZED
OR WITNESSED SIGNATURES ARE NOT ACCEPTABLE.]

                                      A-6<PAGE>

                                                                    EXHIBIT 10.1

                                 FIRST AMENDMENT
                               TO CREDIT AGREEMENT

                  THIS FIRST AMENDMENT TO CREDIT AGREEMENT (this "Amendment"),
is made as of December 19, 2002, by and among HRPT Properties Trust, a real
estate investment trust organized under the laws of the State of Maryland (the
"Borrower"), each of the financial institutions signatory hereto as the initial
Tranche B Lenders (as hereinafter defined), and WACHOVIA BANK, NATIONAL
ASSOCIATION (F/K/A First Union National Bank), as Agent (the "Agent").

                                   WITNESSETH:

                  WHEREAS, the parties hereto are parties to the Credit
Agreement, dated as of April 30, 2001, by and among the Borrower, the Agent, the
other agents named therein and the Lenders thereunder (the "Credit Agreement";
terms defined in the Credit Agreement and not defined herein, unless indicated
otherwise, are used herein with the same meanings as in the Credit Agreement, as
amended hereby); and

                  WHEREAS, the Agent and the Borrower have agreed to certain
amendments to the Credit Agreement, and the Tranche B Lenders party hereto,
constituting the Requisite Lenders, have consented thereto;

                  NOW, THEREFORE, in consideration of the premises and for other
good and valuable consideration, the receipt and adequacy of which are hereby
acknowledged, the parties hereto agree as follows:

I.       AMENDMENTS, ETC.

         A. NEW DEFINITIONS. Article I of the Credit Agreement is hereby amended
to add the following new definitions to be inserted in Section 1.1. in
appropriate alphabetical order:

                  "FIRST AMENDMENT" means the First Amendment, dated as of
         December 19, 2002, amending this Agreement.

                  "TRANCHE B AGENT" means Wachovia Bank, National Association,
         as contractual representative for the Tranche B Lenders under the terms
         of this Agreement, and any of its successors.

                  "TRANCHE B BID RATE LOAN" means a loan made by a Tranche B
         Lender pursuant to Section 2.17.(b).

                  "TRANCHE B BID RATE NOTE" has the meaning set forth in Section
         2.17.(e).

                  "TRANCHE B COMMITMENT" means, as to each Tranche B Lender,
         such Tranche B Lender's obligation to make Tranche B Revolving Loans
         pursuant to Section 2.17.(a) and to issue (in the case of the Tranche B
         Agent) or participate in (in the case of the Tranche B Lenders) Letters
         of Credit issued on and after the Termination Date pursuant

<PAGE>

         to Section 2.17.(d) in an amount up to, but not exceeding (but in the
         case of the Tranche B Lender acting as the Tranche B Agent excluding
         the aggregate amount of participations in the Letters of Credit held
         by other Tranche B Lenders), the amount set forth for such Tranche B
         Lender on its signature page to the First Amendment as such Lender's
         "Tranche B Commitment Amount" or as set forth in the applicable
         Assignment and Acceptance Agreement, as the same may be reduced from
         time to time pursuant to Section 2.12. or as appropriate to reflect
         any assignments to or by such Lender effected in accordance with
         Section 12.5.

                  "TRANCHE B COMMITMENT PERCENTAGE" means, as to each Tranche B
         Lender, the ratio, expressed as a percentage, of (a) the amount of such
         Tranche B Lender's Tranche B Commitment to (b) the aggregate amount of
         the Tranche B Commitments of all Tranche B Lenders hereunder; PROVIDED,
         HOWEVER, that if at the time of determination the Tranche B Commitments
         have terminated or been reduced to zero, the "Tranche B Commitment
         Percentage" of each Tranche B Lender shall be the Tranche B Commitment
         Percentage of such Tranche B Lender in effect immediately prior to such
         termination or reduction.

                  "TRANCHE B LENDER" means each financial institution from time
         to time party hereto as a "Tranche B Lender" as indicated by the
         designation below its signature to the First Amendment, together with
         its successors and permitted assignees; PROVIDED, HOWEVER, that the
         term "Tranche B Lender" shall exclude each Designated Lender when used
         in reference to any Tranche B Loan other than a Tranche B Bid Rate
         Loan, the Tranche B Commitments or terms relating to any Tranche B Loan
         other than a Tranche B Bid Rate Loan and the Tranche B Commitments and
         shall further exclude each Designated Lender for all other purposes
         under the Loan Documents, except that any Designated Lender which funds
         a Tranche B Bid Rate Loan shall, subject to Section 12.5.(e), have the
         rights (including the rights given to a Lender contained in Sections
         12.2. and 12.9.) and obligations of a Tranche B Lender associated with
         holding such Tranche B Bid Rate Loan.

                  "TRANCHE B LOAN" means a Tranche B Revolving Loan, a Tranche B
         Bid Rate Loan or a Tranche B Swingline Loan.

                   "TRANCHE B REQUISITE LENDERS" means, as of any date, Tranche
         B Lenders having at least 66 2/3% of the aggregate amount of the
         Tranche B Commitments (not held by Defaulting Lenders who are not
         entitled to vote), or, if the Tranche B Commitments have been
         terminated or reduced to zero, Tranche B Lenders holding at least 66
         2/3% of the principal amount of the Tranche B Loans and Letter of
         Credit Liabilities relating to Letters of Credit issued after the
         Termination Date (not held by Defaulting Lenders who are not entitled
         to vote).

                  "TRANCHE B REVOLVING LOAN" means a loan made by a Tranche B
         Lender to the Borrower pursuant to Section 2.17.(a).

                  "TRANCHE B REVOLVING NOTE" has the meaning set forth in
         Section 2.17.(e).

                                      -2-

<PAGE>

                  "TRANCHE B SWINGLINE COMMITMENT" means the Swingline Lender's
         obligation to make Tranche B Swingline Loans pursuant to Section
         2.17.(c) in an amount up to, but not exceeding, $25,000,000, as such
         amount may be reduced from time to time in accordance with the terms
         hereof.

                  "TRANCHE B SWINGLINE LOAN" means a loan made by a Swingline
         Lender pursuant to Section 2.17.(c).

                  "TRANCHE B SWINGLINE NOTE" has the meaning set forth in
         Section 2.17.(c).

                  "TRANCHE B TERMINATION DATE" means April 28, 2006, or such
         earlier date to which the Tranche B Termination Date may be shortened
         pursuant to Section 2.17.(f)."

         B. AMENDMENTS TO DEFINITIONS. The definition of the term "Note"
contained in Article I of the Credit Agreement is hereby amended and restated to
read in its entirety as follows:

                  ""NOTE" means a Revolving Note, a Bid Rate Note, a Swingline
         Note, a Tranche B Revolving Note, a Tranche B Bid Rate Note or a
         Tranche B Swingline Note."

         C. NEW SECTION 2.17 OF THE CREDIT AGREEMENT. Article II of the Credit
Agreement is hereby amended to add the following as Section 2.17., which shall
be inserted immediately after Section 2.16.:

         SECTION 2.17.  TRANCHE B COMMITMENT AND LOANS.

                  (a)      REVOLVING TRANCHE B LOANS.

                           (i) Subject to the terms and conditions hereof,
                  during the period from the Termination Date to but excluding
                  the Tranche B Termination Date, each Tranche B Lender
                  severally and not jointly agrees to make Tranche B Revolving
                  Loans to the Borrower in an aggregate principal amount at any
                  one time outstanding up to, but not exceeding, the amount of
                  such Tranche B Lender's Tranche B Commitment. Subject to the
                  terms and conditions of this Agreement, during the period from
                  the Termination Date to the Tranche B Termination Date, the
                  Borrower may borrow, repay and reborrow the Tranche B
                  Revolving Loans hereunder.

                           (ii) The requests for and disbursements of Tranche B
                  Revolving Loans shall be made in accordance with provisions of
                  Sections 2.1.(b) and 2.1.(c); PROVIDED that for such purpose
                  the references therein to "Revolving Loans", "Agent" and
                  "Lender(s)" shall be deemed to be references to "Tranche B
                  Revolving Loans", "Tranche B Agent" and "Tranche B Lender(s)",
                  respectively. Notwithstanding the immediately preceding
                  sentence, upon the Termination Date (i) all outstanding
                  Revolving Loans to Lenders who are not Tranche B Lenders shall
                  be repaid in accordance with Section 2.7. (whether through a
                  borrowing of Tranche B Loans from the Tranche B Lenders or
                  otherwise), and (ii) all Revolving Loans then outstanding to
                  any Tranche B Lender shall be deemed to be

                                      -3-

<PAGE>

                  Tranche B Revolving Loans of the same Type and, in the case
                  of all LIBOR Loans then outstanding, of the same Interest
                  Period then in effect. As of the Termination Date, such
                  Tranche B Revolving Loans shall be allocated among the
                  Tranche B Lenders in accordance with their respective
                  Tranche B Commitment Percentages. Each Tranche B Lender
                  agrees to make such payments to the other Tranche B Lenders
                  (or, if necessary to effectuate the purposes hereof, to
                  Lenders who are not Tranche B Lenders) upon the Termination
                  Date in such amounts as are necessary to effect such
                  allocation. All such payments shall be made to the Agent or
                  the Tranche B Agent, as the case may be, for the account of
                  the Person to be paid.

                  (b)      TRANCHE B BID RATE LOANS.

                           (i) So long as the Borrower maintains an Investment
                  Grade Rating, in addition to borrowings of Tranche B Revolving
                  Loans, at any time during the period from the Termination Date
                  to, but excluding, the Tranche B Termination Date the Borrower
                  may, as set forth in this Section 2.17.(b), request the
                  Tranche B Lenders to make offers to make Tranche B Bid Rate
                  Loans to the Borrower in Dollars. The Tranche B Lenders may,
                  but shall have no obligation to, make such offers and the
                  Borrower may, but shall have no obligation to, accept any such
                  offers in the manner set forth in this Section 2.17.(b).
                  Except for the purpose and to the extent expressly stated in
                  Section 2.12., the amount of any Tranche B Bid Rate Loan made
                  by any Tranche B Lender shall not constitute a utilization of
                  such Tranche B Lender's Tranche B Commitment.

                           (ii) The requests for, quotes for, notices relating
                  to, acceptances of, and obligation to make Tranche B Bid Rate
                  Loans, shall be in accordance with the provisions of Sections
                  2.2.(b) through 2.2.(f); PROVIDED that for such purpose the
                  references therein to "Bid Rate Loans", "Lender(s)", "Agent",
                  "Commitment" for such purpose shall be deemed to be references
                  to "Tranche B Bid Rate Loans", "Tranche B Lender(s)", "Tranche
                  B Agent" and "Tranche B Commitment", respectively.

                  (c)      TRANCHE B SWINGLINE LOANS.

                           (i) Subject to the terms and conditions hereof,
                  during the period from the Termination Date to but excluding
                  the Tranche B Termination Date, the Swingline Lender agrees to
                  make Tranche B Swingline Loans to the Borrower in an aggregate
                  principal amount at any one time outstanding up to, but not
                  exceeding, the amount of the Tranche B Swingline Commitment.
                  If at any time the aggregate principal amount of the Tranche B
                  Swingline Loans outstanding at such time exceeds the Tranche B
                  Swingline Commitment in effect at such time, the Borrower
                  shall immediately pay the Tranche B Agent for the account of
                  the Swingline Lender the amount of such excess. Subject to the
                  terms and conditions of this Agreement, the Borrower may
                  borrow, repay and reborrow Tranche B Swingline Loans
                  hereunder. The Tranche B Swingline Loans shall, in addition to

                                      -4-

<PAGE>

                  this Agreement, be evidenced by the Tranche B Swingline Note
                  substantially in the form of Exhibit Q (the "Tranche B
                  Swingline Note").

                           (ii) The procedure for borrowing, the interest rates
                  applicable to, amounts of, and repayment and participations of
                  Tranche B Swingline Loans shall be in accordance with the
                  provisions of Sections 2.3.(b) through 2.3.(e); PROVIDED that
                  for such purpose the references therein to "Agent", "Lender",
                  "Commitment", "Swingline Loan" and "Termination Date" shall be
                  deemed to be references to "Tranche B Agent", "Tranche B
                  Lender", "Tranche B Commitment", "Tranche B Swingline Loan"
                  and "Tranche B Termination Date", respectively.

                  (d) LETTERS OF CREDIT. Subject to the terms and conditions of
         this Agreement, the Tranche B Agent, on behalf of the Tranche B Lenders
         agrees to issue for the account of the Borrower during the period from
         and including the Termination Date to, but excluding, the date 30 days
         prior to the Tranche B Termination Date one or more Letters of Credit
         upon the terms and conditions set forth in Section 2.4.; PROVIDED that
         for such purpose the references in Section 2.4. to "Agent",
         "Termination Date", "Commitment Percentage", "Revolving Loans",
         "Commitment", "Requisite Lenders" and "Lender(s)" shall be deemed to be
         references to "Tranche B Agent", "Tranche B Termination Date", "Tranche
         B Commitment Percentage", "Tranche B Revolving Loans", "Tranche B
         Commitment", "Tranche B Requisite Lenders" and "Tranche B Lender(s)",
         respectively.

                  (e) INTEREST ON TRANCHE B LOANS; PREPAYMENTS; TRANCHE B
         REVOLVING NOTES; REDUCTION OF TRANCHE B COMMITMENTS; ETC.

                          (i) The provisions of Sections 2.5. through 2.10.,
                  2.11.(c), 2.11.(d), 2.12., and 2.14. shall also apply to
                  Tranche B Loans; PROVIDED that for such purpose the
                  references therein to terms relating to Loans shall be
                  deemed to refer to terms relating to Tranche B Loans,
                  including without limitation, the terms "Agent", "Bid Rate
                  Loan", "Lender", "Loan", "Termination Date", "Commitments"
                  for such purpose shall be deemed to refer to "Tranche B
                  Agent", "Tranche B Bid Rate Loan", "Tranche B Lender",
                  "Tranche B Loan", "Tranche B Termination Date", and "Tranche
                  B Commitments", respectively.

                           (ii) The Tranche B Revolving Loans made by each
                  Tranche B Lender shall, in addition to this Agreement, also be
                  evidenced by a promissory note of the Borrower substantially
                  in the form of Exhibit R (each a "Tranche B Revolving Note"),
                  payable to the order of such Tranche B Lender in a principal
                  amount equal to the amount of its Tranche B Commitment as
                  originally in effect and otherwise duly completed. The Tranche
                  B Bid Rate Loans made by any Tranche B Lender shall, in
                  addition to this Agreement, also be evidenced by a promissory
                  note of the Borrower substantially in the form of Exhibit S
                  (each a "Tranche B Bid Rate Note"), payable to the order of
                  such Lender and otherwise duly completed.

                                      -5-

<PAGE>

                  (f) EARLIER TRANCHE B TERMINATION DATE. The Borrower may
         request that the Tranche B Agent and the Tranche B Lenders shorten the
         current Tranche B Termination Date by one (1) year by executing and
         delivering to the Tranche B Agent no later than January 30, 2005, a
         written request substantially in the form of Exhibit M (with
         appropriate changes relating to the Tranche B Loans). Once given, such
         cancellation request shall be irrevocable by, and binding on, the
         Borrower. The Tranche B Agent shall forward to each Tranche B Lender a
         copy of such cancellation request delivered to the Tranche B Agent
         promptly after receipt thereof. If the Borrower fails to deliver a
         cancellation request to the Tranche B Agent by such date, then the
         Tranche B Termination Date shall remain unchanged. If the Tranche B
         Termination Date is not so shortened, the Borrower agrees to pay to the
         Tranche B Agent, on or before January 30, 2005, for the account of each
         Tranche B Lender a fee equal to one-quarter of one percent (0.25%) of
         the amount of such Tranche B Lender's Tranche B Commitment (whether or
         not utilized).

                  (g) AMOUNT LIMITATIONS. Notwithstanding any other term of this
         Agreement or any other Loan Document, at no time after the Termination
         Date may:

                           (i) The aggregate principal amount of all outstanding
                  Tranche B Revolving Loans, together with the aggregate
                  principal amount of all outstanding Tranche B Bid Rate Loans
                  and the aggregate principal amount of all outstanding Tranche
                  B Swingline Loans and the aggregate amount of all Letter of
                  Credit Liabilities, exceed the aggregate amount of the Tranche
                  B Commitments at such time; or

                           (ii) The aggregate principal amount of all
                  outstanding Tranche B Bid Rate Loans exceed the lesser of (i)
                  $200,000,000 or (ii) 50% of the aggregate amount of the
                  Tranche B Commitments at such time.

                  (h) INCREASE OF TRANCHE B COMMITMENTS. The Borrower shall have
         the right to request increases in the aggregate amount of the Tranche B
         Commitments (PROVIDED that after giving effect to the aggregate amount
         of increases in the Tranche B Commitments pursuant to this Section, the
         aggregate amount of Tranche B Commitments shall not exceed
         $625,000,000) by providing written notice to the Tranche B Agent, which
         notice shall be irrevocable once given. Each such increase in the
         Tranche B Commitments must be an aggregate minimum amount of
         $20,000,000 and integral multiples of $1,000,000 in excess thereof. The
         Tranche B Agent shall promptly notify each Tranche B Lender of any such
         request. Each existing Tranche B Lender shall have the right to
         increase its Tranche B Commitment by an amount so that such Tranche B
         Lender's Tranche B Commitment Percentage shall not be decreased as a
         result of such requested increase in the Tranche B Commitments. Each
         Tranche B Lender shall notify the Tranche B Agent within 10 Business
         Days after receipt of the Tranche B Agent's notice whether such Lender
         wishes to increase the amount of its Tranche B Commitment. If a Tranche
         B Lender fails to deliver any such notice to the Tranche B Agent within
         such time period, then such Tranche B Lender shall be deemed to have
         declined to increase its Tranche B Commitment. No Tranche B Lender
         shall be required to increase its Tranche B Commitment and any new
         Tranche B Lender(s) becoming a party to this

                                      -6-

<PAGE>

         Agreement in connection with any such requested increase must be an
         Eligible Assignee. In the event a new Tranche B Lender or Tranche B
         Lenders become a party to this Agreement, or if any existing Tranche B
         Lender agrees to increase its Tranche B Commitment, such Tranche B
         Lender shall on the date it becomes a Tranche B Lender hereunder (or
         increases its Tranche B Commitment, in the case of an existing Tranche
         B Lender) (and as a condition thereto) purchase from the other Tranche
         B Lenders its Tranche B Commitment Percentage (as determined after
         giving effect to the increase of Tranche B Commitments) of any
         outstanding Tranche B Revolving Loans, by making available to the
         Tranche B Agent for the account of such other Tranche B Lenders at the
         Principal Office, in same day funds, an amount equal to the sum of (A)
         the portion of the outstanding principal amount of such Tranche B
         Revolving Loans to be purchased by such Tranche B Lender plus (B) the
         aggregate amount of payments previously made by the other Tranche B
         Lenders under Section 2.4.(j) (as incorporated by Section 2.17.(d))
         which have not been repaid plus (C) interest accrued and unpaid to and
         as of such date on such portion of the outstanding principal amount of
         such Tranche B Revolving Loans. The Borrower shall pay to the Tranche
         B Lenders amounts payable, if any, to such Tranche B Lenders under
         Section 4.4. as a result of the prepayment of any such Tranche B
         Revolving Loans. No increase of the Tranche B Commitments may be
         effected under this subsection if either (x) a Default or Event of
         Default shall be in existence on the effective date of such increase
         or (y) any representation or warranty made or deemed made by the
         Borrower or any other Loan Party in any Loan Document to which any
         such Loan Party is a party is not (or would not be) true or correct on
         the effective date of such increase (except for representations or
         warranties which expressly relate solely to an earlier date). In
         connection with any increase in the aggregate amount of the Tranche B
         Commitments pursuant to this subsection, (a) any Tranche B Lender
         becoming a party hereto shall execute such documents and agreements as
         the Tranche B Agent may reasonably request and (b) the Borrower shall
         make appropriate arrangements so that each new Tranche B Lender, and
         any existing Tranche B Lender increasing its Tranche B Commitment,
         receives a new or replacement Tranche B Note, as appropriate, in the
         amount of such Tranche B Lender's Tranche B Commitment within 2
         Business Days of the effectiveness of the applicable increase in the
         aggregate amount of Tranche B Commitments.

                  (i) APPLICATION OF AGREEMENT TO TRANCHE B LOANS. The
         provisions of Articles I., III. (except for Section 3.6.(c)) and IV.,
         Sections 5.2. and 5.3., Articles VI., VII., VIII., IX., X., XI. and
         XII. and defined terms used therein and in the Exhibits referenced
         therein shall be interpreted, where necessary, to give effect to the
         Tranche B Loans and Letters of Credit contemplated under this Section
         2.17. In the event that defined terms used in this Article II., to the
         extent applicable to Tranche B Loans, are inconsistent with the
         provisions of this Section 2.17., such terms shall be interpreted,
         where necessary, to give effect to such provisions.

                                      -7-

<PAGE>

         D. AMENDMENT TO SECTION 3.6. Section 3.6. of the Credit Agreement is
hereby amended to add the following subsection (e), which shall be inserted
immediately after subsection (d) thereof:

                  (e) TRANCHE B MATURITY FEE. If the Tranche B Termination Date
         is not shortened in accordance with Section 2.17.(f), the Borrower
         agrees to pay to the Tranche B Agent for the account of each Tranche B
         Lender a fee equal to one-quarter of one percent (0.25%) of the amount
         of such Tranche B Lender's Tranche B Commitment (whether or not
         utilized). Such fee shall be due and payable in full on January 30,
         2005.

         E. ADDITIONAL EXHIBITS. The Credit Agreement is hereby amended to add
Exhibits Q, R and S thereto, as set forth as Exhibits Q, R and S, respectively,
to this Amendment.

         F. WAIVER OF MATURITY FEE. Each Tranche B Lender hereby irrevocably
waives its right to receive payment of its share of the maturity fee otherwise
payable by the Borrower pursuant to Section 3.6.(c) of the Credit Agreement.

         G. RESTRICTION ON ASSIGNMENT. Notwithstanding anything to the contrary
contained in the Credit Agreement (including, but not limited to, Section 12.5.
thereof), or any of the other Loan Documents, any Lender which is also a Tranche
B Lender which effectuates an assignment under Section 12.5.(d) of the Credit
Agreement to an Assignee shall assign an equal percentage of both its Commitment
and its Tranche B Commitment to the applicable Assignee in connection with any
such assignment.

II.      REPRESENTATIONS.

                  The Borrower represents and warrants to the Agent and the
Lenders as follows:

                  (a) After giving effect to the amendments to the Credit
         Agreement set forth in this Amendment, no Default or Event of Default
         has occurred and is continuing; and

                  (b) The representations and warranties made or deemed made by
         the Borrower and each other Loan Party in the Loan Documents to which
         any of them is a party, are true and correct on and as of the date of
         this Amendment with the same force and effect as if made on and as of
         such date except to the extent that such representations and warranties
         expressly relate solely to an earlier date (in which case such
         representations and warranties shall have been true and accurate on and
         as of such earlier date) and except for changes in factual
         circumstances specifically and expressly permitted under the Credit
         Agreement.

III.     EFFECTIVENESS.

                  This Amendment shall become effective upon the occurrence of
each of the following events:

                  (a) This Amendment shall be duly executed and delivered by the
         Borrower and the Lenders constituting the Requisite Lenders;

                                      -8-

<PAGE>

                  (b) The Borrower shall have executed and delivered to (i) each
         Tranche B Lender a Tranche B Revolving Note and a Tranche B Bid Rate
         Note and (ii) the Swingline Lender, a Tranche B Swingline Note;

                  (c) Each of the Guarantors shall have executed and delivered a
         Reaffirmation of Guaranty in form and substance satisfactory to the
         Agent;

                  (d) The Agent shall have received an opinion of Sullivan &
         Worcester LLP, counsel to the Loan Parties, addressed to the Agent, the
         Tranche B Agent, the Lenders, the Tranche B Lenders and the Swingline
         Lender in form and substance satisfactory to Agent and the Tranche B
         Agent; and

                  (e) The Borrower shall have paid to the Tranche B Agent for
         the account of each Tranche B Lender an upfront fee equal to
         one-quarter of one percent (0.25%) of the amount of such Tranche B
         Lender's initial Tranche B Commitment.

IV.      GENERAL.

         A. The Credit Agreement, as amended by this Amendment, is ratified and
confirmed and shall continue in full force and effect. This Amendment shall
constitute a Loan Document.

         B. THIS AMENDMENT SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE
WITH, THE LAWS OF THE STATE OF NEW YORK APPLICABLE TO CONTRACTS EXECUTED, AND TO
BE FULLY PERFORMED, IN SUCH STATE.

         C. This Amendment may be executed in any number of counterparts and by
different parties hereto in separate counterparts, each of which when so
executed and delivered shall be deemed an original, but all of which
counterparts together shall constitute but one and the same instrument.

         D. The parties hereto acknowledge and agree as follows:

                  THE AMENDED AND RESTATED DECLARATION OF TRUST ESTABLISHING THE
BORROWER, DATED JULY 1, 1994, A COPY OF WHICH, TOGETHER WITH ALL AMENDMENTS
THERETO (THE "DECLARATION"), IS DULY FILED IN THE OFFICE OF THE STATE DEPARTMENT
OF ASSESSMENTS AND TAXATION OF MARYLAND, PROVIDES THAT THE NAME "HRPT PROPERTIES
TRUST" REFERS TO THE TRUSTEES UNDER THE DECLARATION COLLECTIVELY AS TRUSTEES,
BUT NOT INDIVIDUALLY OR PERSONALLY, AND THAT NO TRUSTEE, OFFICER, SHAREHOLDER,
EMPLOYEE OR AGENT OF THE BORROWER SHALL BE HELD TO ANY PERSONAL LIABILITY,
JOINTLY OR SEVERALLY, FOR ANY OBLIGATION OF, OR CLAIM AGAINST, THE BORROWER. ALL
PERSONS DEALING WITH THE BORROWER, IN ANY WAY, SHALL LOOK ONLY TO THE ASSETS OF
THE BORROWER FOR THE PAYMENT OF ANY SUM OR THE PERFORMANCE OF ANY OBLIGATION.
THE PROVISIONS OF THIS SECTION SHALL NOT LIMIT ANY OBLIGATIONS OF ANY LOAN PARTY
OTHER THAN THE BORROWER.

                                      -9-

<PAGE>

                  IN WITNESS WHEREOF, the parties hereto have caused this First
Amendment to be executed by their authorized officers all as of the day and year
first above written.

                                            HRPT Properties Trust

                                            By: /s/
                                                --------------------------------
                                                Name:
                                                     ---------------------------
                                                Title:
                                                      --------------------------

                                            Attest: /s/
                                                   -----------------------------
                                                Name:
                                                     ---------------------------
                                                Title:
                                                      --------------------------

                       [Signatures Continued on Next Page]

<PAGE>

       [SIGNATURE PAGE TO FIRST AMENDMENT TO CREDIT AGREEMENT DATED AS OF
                  DECEMBER 19, 2002 WITH HRPT PROPERTIES TRUST]

                                            WACHOVIA BANK, NATIONAL ASSOCIATION,
                                               as Agent, as Tranche B Agent, as
                                               a Lender, as a Tranche B Lender
                                               and as Swingline Lender

                                            By: /s/
                                                --------------------------------
                                                Name:
                                                     ---------------------------
                                                Title:
                                                      --------------------------

                                            Tranche B Commitment Amount:

                                            $72,000,000

                                            Lending Office (all Types of Loans):

                                            Wachovia Bank, National Association
                                            301 South College Street, 16th Floor
                                            Charlotte, North Carolina  28288
                                            Attn:  Rex Rudy
                                            Telecopier:       704-383-6205
                                            Telephone:        704-383-6506

                       [Signatures Continued on Next Page]

<PAGE>

       [SIGNATURE PAGE TO FIRST AMENDMENT TO CREDIT AGREEMENT DATED AS OF
                  DECEMBER 19, 2002 WITH HRPT PROPERTIES TRUST]

                                          WELLS FARGO BANK, NATIONAL ASSOCIATION

                                          By: /s/ Douglas S. Novitch
                                             ---------------------------------
                                             Name:  Douglas S. Novitch
                                             Title:   Vice President

                                          Tranche B Commitment Amount:

                                          $60,000,000

                                          Lending Office (all Types of Loans):

                                          Wells Fargo Bank, National Association
                                          121 High Street, 5th Floor
                                          Boston, MA  02110
                                          Attn:  Douglas S. Novitch
                                          Telecopier:       617-772-9337
                                          Telephone:        617-574-6307

                       [Signatures Continued on Next Page]

<PAGE>

       [SIGNATURE PAGE TO FIRST AMENDMENT TO CREDIT AGREEMENT DATED AS OF
                 DECEMBER 19, 2002 WITH HRPT PROPERTIES TRUST]

                                            COMMERZBANK AG, NEW YORK AND
                                            GRAND CAYMAN BRANCHES

                                            By: /s/
                                                --------------------------------
                                                Name:
                                                     ---------------------------
                                                Title:
                                                      --------------------------

                                            Tranche B Commitment Amount:

                                            $60,000,000

                                            Lending Office (all Types of Loans):

                                            Commerzbank AG, New York Branch
                                            2 World Financial Center
                                            New York, New York 10281
                                            Attn: Christian Berry
                                            Telecopier:       212-266-7530
                                            Telephone:        212-266-7206

                       [Signatures Continued on Next Page]

<PAGE>

       [SIGNATURE PAGE TO FIRST AMENDMENT TO CREDIT AGREEMENT DATED AS OF
                 DECEMBER 19, 2002 WITH HRPT PROPERTIES TRUST]

                                            THE BANK OF NEW YORK

                                            By: /s/
                                                --------------------------------
                                                Name:
                                                     ---------------------------
                                                Title:
                                                      --------------------------

                                            Tranche B Commitment Amount:

                                            $35,000,000

                                            Lending Office (all Types of Loans):

                                            The Bank of New York
                                            One Wall Street, 21st Floor
                                            New York, New York  10286
                                            Attn:  David V. Fowler
                                            Telecopier:       212-809-9526
                                            Telephone:        212-635-8113

                       [Signatures Continued on Next Page]

<PAGE>

       [SIGNATURE PAGE TO FIRST AMENDMENT TO CREDIT AGREEMENT DATED AS OF
                 DECEMBER 19, 2002 WITH HRPT PROPERTIES TRUST]

                                            AMSOUTH BANK

                                            By: /s/ Katherine M. Allen
                                               ---------------------------------
                                               Name:  Katherine M. Allen
                                               Title: Vice President

                                            Tranche B Commitment Amount:

                                            $25,000,000

                                            Lending Office (all Types of Loans):

                                            AmSouth Bank
                                            1900 5th Avenue North, 9th Floor
                                            Birmingham, AL  35203
                                            Attn:  David Ellis
                                            Telecopier:       205-326-4075
                                            Telephone:        205-581-7646

                       [Signatures Continued on Next Page]

<PAGE>

       [SIGNATURE PAGE TO FIRST AMENDMENT TO CREDIT AGREEMENT DATED AS OF
                 DECEMBER 19, 2002 WITH HRPT PROPERTIES TRUST]

                                            CITIZENS BANK OF MASSACHUSETTS

                                            By: /s/
                                                --------------------------------
                                                Name:
                                                     ---------------------------
                                                Title:
                                                      --------------------------

                                            Tranche B Commitment Amount:

                                            $20,000,000

                                            Lending Office (all Types of Loans):

                                            Citizens Bank
                                            28 State Street, 14th Floor
                                            Boston, Massachusetts 02109
                                            Attn: Daniel R. Ouellette
                                            Telecopier:       617-725-5695
                                            Telephone:        617-725-5602

                       [Signatures Continued on Next Page]

<PAGE>

       [SIGNATURE PAGE TO FIRST AMENDMENT TO CREDIT AGREEMENT DATED AS OF
                  DECEMBER 19, 2002 WITH HRPT PROPERTIES TRUST]

                                            SUNTRUST BANK

                                            By: /s/ Blake K. Thompson
                                               ---------------------------------
                                               Name:  Blake K. Thompson
                                               Title: Vice President

                                            Tranche B Commitment Amount:

                                            $30,000,000

                                            Lending Office (all Types of Loans):

                                            SunTrust Bank
                                            8245 Boone Blvd
                                            Suite 820
                                            Vienna, VA  22182
                                            Attn:  Nazmia Sediqi
                                            Telecopier:       703-902-9245/9190
                                            Telephone:        703-902-9048

                       [Signatures Continued on Next Page]

<PAGE>

       [SIGNATURE PAGE TO FIRST AMENDMENT TO CREDIT AGREEMENT DATED AS OF
                 DECEMBER 19, 2002 WITH HRPT PROPERTIES TRUST]

                                            THE GOVERNOR AND COMPANY OF
                                            THE BANK OF IRELAND

                                            By: /s/
                                                --------------------------------
                                                Name:
                                                     ---------------------------
                                                Title:
                                                      --------------------------

                                            By: /s/
                                                --------------------------------
                                                Name:
                                                     ---------------------------
                                                Title:
                                                      --------------------------

                                            Tranche B Commitment Amount:

                                            $15,000,000

                                            Lending Office (all Types of Loans):

                                            The Governor and Company of
                                            the Bank of Ireland
                                            LaTouche House
                                            International Financial Services
                                            Centre
                                            Dublin 1, Ireland
                                            Attn:  Niamh O'Flynn
                                            Telecopier:       011-353-1-8290129
                                            Telephone:        011-353-1-6093491

                       [Signatures Continued on Next Page]

<PAGE>

       [SIGNATURE PAGE TO FIRST AMENDMENT TO CREDIT AGREEMENT DATED AS OF
                 DECEMBER 19, 2002 WITH HRPT PROPERTIES TRUST]

                                            PNC BANK, NATIONAL ASSOCIATION

                                            By: /s/
                                                --------------------------------
                                                Name:
                                                     ---------------------------
                                                Title:
                                                      --------------------------

                                            Tranche B Commitment Amount:

                                            $25,000,000

                                            Lending Office (all Types of Loans):

                                            PNC Bank, National Association
                                            249 Fifth Avenue
                                            Mail Stop P1-POPP-19-2
                                            Pittsburgh, PA 15222-2707
                                            Attn:  Charlene Markoff
                                            Telecopier:         412-768-3930
                                            Telephone:          412-762-4464

                       [Signatures Continued on Next Page]

<PAGE>

       [SIGNATURE PAGE TO FIRST AMENDMENT TO CREDIT AGREEMENT DATED AS OF
                 DECEMBER 19, 2002 WITH HRPT PROPERTIES TRUST]

                                            CHEVY CHASE BANK, F.S.B.

                                            By: /s/
                                                --------------------------------
                                                Name:
                                                     ---------------------------
                                                Title:
                                                      --------------------------

                                            Tranche B Commitment Amount:

                                            $15,000,000

                                            Lending Office (all Types of Loans):

                                            Chevy Chase Bank, F.S.B.
                                            7501 Wisconsin Avenue
                                            Bethesda, MD  20814
                                            Attn:  Paula Moriarty-Storch
                                            Telecopier:       240-497-7714
                                            Telephone:        240-497-7758

                       [Signatures Continued on Next Page]

<PAGE>

       [SIGNATURE PAGE TO FIRST AMENDMENT TO CREDIT AGREEMENT DATED AS OF
                 DECEMBER 19, 2002 WITH HRPT PROPERTIES TRUST]

                                            EASTERN BANK

                                            By: /s/ Richard C. Muraida
                                               ---------------------------------
                                               Name:  Richard C. Muraida
                                               Title: Vice President

                                            Tranche B Commitment Amount:

                                            $15,000,000

                                            Lending Office (all Types of Loans):

                                            Eastern Bank
                                            265 Franklin Street
                                            Second Floor BOS210
                                            Boston MA  02110
                                            Attn:  Richard Muraida
                                            Telecopier:       617-897-1093
                                            Telephone:        617-897-1019

                       [Signatures Continued on Next Page]

<PAGE>

       [SIGNATURE PAGE TO FIRST AMENDMENT TO CREDIT AGREEMENT DATED AS OF
                 DECEMBER 19, 2002 WITH HRPT PROPERTIES TRUST]

                                            NATIONAL BANK OF EGYPT,
                                            NEW YORK BRANCH

                                            By: /s/ Carmelo L. Foti
                                               ---------------------------------
                                               Name: Carmelo L. Foti
                                               Title: Vice President

                                            By: /s/ Rami El-Rifai
                                               ---------------------------------
                                               Name: Rami El-Rifai
                                               Title: Assistant Vice President

                                            Tranche B Commitment Amount:

                                            $10,000,000

                                            Lending Office (all Types of Loans):

                                            National Bank of Egypt
                                            New York Branch
                                            40 East 52nd Street
                                            New York, New York 10022
                                            Attn: Vernon Hatton
                                            Telecopier:       212-755-6944
                                            Telephone:        212-326-8000

                       [Signatures Continued on Next Page]

<PAGE>

       [SIGNATURE PAGE TO FIRST AMENDMENT TO CREDIT AGREEMENT DATED AS OF
                 DECEMBER 19, 2002 WITH HRPT PROPERTIES TRUST]

                                            RZB FINANCE LLC

                                            By: /s/
                                                --------------------------------
                                                Name:
                                                     ---------------------------
                                                Title:
                                                      --------------------------

                                            By: /s/
                                                --------------------------------
                                                Name:
                                                     ---------------------------
                                                Title:
                                                      --------------------------

                                            Tranche B Commitment Amount:

                                            $10,000,000

                                            Lending Office (all Types of Loans):

                                            RZB Finance LLC
                                            1133 Avenue of the Americas -
                                            16th Floor
                                            New York, New York 10030
                                            Attn: Chris Staples
                                            Telecopier:       (212) 944-2093
                                            Telephone:        (212) 845-4135

                       [Signatures Continued on Next Page]

<PAGE>

       [SIGNATURE PAGE TO FIRST AMENDMENT TO CREDIT AGREEMENT DATED AS OF
                 DECEMBER 19, 2002 WITH HRPT PROPERTIES TRUST]

                                            BANK LEUMI USA

                                            By: /s/ Charles C. D'Amico
                                               ---------------------------------
                                               Name:  Charles C. D'Amico
                                               Title: Vice President

                                            Tranche B Commitment Amount:

                                            $5,000,000

                                            Lending Office (all Types of Loans):

                                            Bank Leumi USA
                                            562 Fifth Avenue
                                            New York NY  10036
                                            Attn:  Charles C. D'Amico
                                            Telecopier:       212-626-1239
                                            Telephone:        212-626-1220

<PAGE>

                                    EXHIBIT Q

                        FORM OF TRANCHE B SWINGLINE NOTE

$25,000,000.00                                               _____________, 200_

         FOR VALUE RECEIVED, the undersigned, HRPT PROPERTIES TRUST, a Maryland
real estate investment trust (the "Borrower"), hereby promises to pay to the
order of WACHOVIA BANK, NATIONAL ASSOCIATION (the "Swingline Lender") at its
address at One Wachovia Center, 301 South College Street, Charlotte, North
Carolina 28288, or at such other address as may be specified in writing by the
Swingline Lender to the Borrower, the principal sum of TWENTY-FIVE MILLION AND
NO/100 DOLLARS ($25,000,000.00) (or such lesser amount as shall equal the
aggregate unpaid principal amount of Tranche B Swingline Loans made by the
Swingline Lender to the Borrower under the Credit Agreement), on the dates and
in the principal amounts provided in the Credit Agreement, and to pay interest
on the unpaid principal amount owing hereunder, at the rates and on the dates
provided in the Credit Agreement.

         The date and amount of each Tranche B Swingline Loan, and each payment
made on account of the principal thereof, shall be recorded by the Swingline
Lender on its books and, prior to any transfer of this Note, endorsed by the
Swingline Lender on the schedule attached hereto or any continuation thereof,
PROVIDED that the failure of the Swingline Lender to make any such recordation
or endorsement shall not affect the obligations of the Borrower to make a
payment when due of any amount owing under the Credit Agreement or hereunder in
respect of the Tranche B Swingline Loans.

         This Note is the Tranche B Swingline Note referred to in the Credit
Agreement dated as of April 30, 2001 (as amended, restated, supplemented or
otherwise modified from time to time, the "Credit Agreement"), by and among the
Borrower, the financial institutions party thereto and their assignees under
Section 12.5. thereof (the "Lenders"), Wachovia Bank, National Association, as
Agent, and the other parties thereto, and evidences Tranche B Swingline Loans
made to the Borrower thereunder. Terms used but not otherwise defined in this
Note have the respective meanings assigned to them in the Credit Agreement.

         The Credit Agreement provides for the acceleration of the maturity of
this Note upon the occurrence of certain events and for prepayments of Tranche B
Swingline Loans upon the terms and conditions specified therein.

         THIS NOTE SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE
LAWS OF THE STATE OF NEW YORK APPLICABLE TO CONTRACTS EXECUTED, AND TO BE FULLY
PERFORMED, IN SUCH STATE.

         The Borrower hereby waives presentment for payment, demand, notice of
demand, notice of non-payment, protest, notice of protest and all other similar
notices.

<PAGE>

         Time is of the essence for this Note.

         IN WITNESS WHEREOF, the undersigned has executed and delivered this
Tranche B Swingline Note under seal as of the date first written above.

                                 HRPT PROPERTIES TRUST

                                 By:
                                     -------------------------------------------
                                     Name:
                                          --------------------------------------
                                     Title:
                                           -------------------------------------

                                 Attest:
                                        ----------------------------------------
                                        Name:
                                             -----------------------------------
                                        Title:
                                               ---------------------------------

                                 [CORPORATE SEAL]

                                      Q-2

<PAGE>

                      SCHEDULE OF TRANCHE B SWINGLINE LOANS

                           This Note evidences Tranche B Swingline Loans made
         under the within-described Credit Agreement to the Borrower, on the
         dates and in the principal amounts set forth below, subject to the
         payments and prepayments of principal set forth below:

<TABLE>
<CAPTION>
                    PRINCIPAL                         UNPAID
                    AMOUNT OF     AMOUNT PAID        PRINCIPAL        NOTATION
DATE OF LOAN           LOAN        OR PREPAID         AMOUNT           MADE BY
------------        ---------     -----------        ---------        ---------
<S>                 <C>           <C>                <C>              <C>
</TABLE>

                                      Q-3

<PAGE>

                                    EXHIBIT R

                        FORM OF TRANCHE B REVOLVING NOTE

$____________________                                      _______________, 200_

         FOR VALUE RECEIVED, the undersigned, HRPT PROPERTIES TRUST, a Maryland
real estate investment trust (the "Borrower"), hereby promises to pay to the
order of ____________________ (the "Tranche B Lender"), in care of Wachovia
Bank, National Association, as Tranche B Agent (the "Agent") to Wachovia Bank,
National Association, One Wachovia Center, 301 South College Street, Charlotte,
North Carolina 28288, or at such other address as may be specified in writing by
the Agent to the Borrower, the principal sum of ________________ AND ____/100
DOLLARS ($____________) (or such lesser amount as shall equal the aggregate
unpaid principal amount of Tranche B Revolving Loans made by the Tranche B
Lender to the Borrower under the Credit Agreement (as herein defined)), on the
dates and in the principal amounts provided in the Credit Agreement, and to pay
interest on the unpaid principal amount owing hereunder, at the rates and on the
dates provided in the Credit Agreement.

         The date and amount of each Tranche B Revolving Loan made by the
Tranche B Lender to the Borrower, and each payment made on account of the
principal thereof, shall be recorded by the Tranche B Lender on its books and,
prior to any transfer of this Note, endorsed by the Tranche B Lender on the
schedule attached hereto or any continuation thereof, PROVIDED that the failure
of the Tranche B Lender to make any such recordation or endorsement shall not
affect the obligations of the Borrower to make a payment when due of any amount
owing under the Credit Agreement or hereunder in respect of the Tranche B
Revolving Loans made by the Tranche B Lender.

         This Note is one of the Tranche B Revolving Notes referred to in the
Credit Agreement dated as of April 30, 2001 (as amended, restated, supplemented
or otherwise modified from time to time, the "Credit Agreement"), by and among
the Borrower, the financial institutions party thereto and their assignees under
Section 12.5. thereof, the Agent, and the other parties thereto. Capitalized
terms used herein, and not otherwise defined herein, have their respective
meanings given them in the Credit Agreement.

         The Credit Agreement provides for the acceleration of the maturity of
this Note upon the occurrence of certain events and for prepayments of Loans
upon the terms and conditions specified therein.

         Except as permitted by Section 12.5.(d) of the Credit Agreement, this
Note may not be assigned by the Tranche B Lender to any Person.

<PAGE>

         This Note shall be governed by, and construed in accordance with, the
laws of the State of NEW YORK APPLICABLE TO CONTRACTS EXECUTED, AND TO BE FULLY
PERFORMED, IN SUCH STATE.

         The Borrower hereby waives presentment for payment, demand, notice of
demand, notice of non-payment, protest, notice of protest and all other similar
notices.

         Time is of the essence for this Note.

         IN WITNESS WHEREOF, the undersigned has executed and delivered this
Tranche B Revolving Note under seal as of the date first written above.

                             HRPT PROPERTIES TRUST

                             By:
                                 -----------------------------------------------
                                 Name:
                                      ------------------------------------------
                                 Title:
                                       -----------------------------------------

                                      R-2

<PAGE>

                      SCHEDULE OF TRANCHE B REVOLVING LOANS

                  This Note evidences Tranche B Revolving Loans made under the
within-described Credit Agreement to the Borrower, on the dates, in the
principal amounts, bearing interest at the rates and maturing on the dates set
forth below, subject to the payments and prepayments of principal set forth
below:

<TABLE>
<CAPTION>
           PRINCIPAL               MATURITY     AMOUNT      UNPAID
DATE OF    AMOUNT OF   INTEREST     DATE OF     PAID OR    PRINCIPAL    NOTATION
 LOAN         LOAN       RATE        LOAN       PREPAID     AMOUNT      MADE BY
-------    ---------   --------    --------     -------    ---------    --------
<S>        <C>         <C>         <C>          <C>        <C>          <C>
</TABLE>

                                      R-3

<PAGE>

                                    EXHIBIT S

                         FORM OF TRANCHE B BID RATE NOTE

                                                              ____________, 200_

         FOR VALUE RECEIVED, the undersigned, HRPT PROPERTIES TRUST, a Maryland
real estate investment trust (the "Borrower"), hereby promises to pay to the
order of ________________ (the "Tranche B Lender"), in care of Wachovia Bank,
National Association, as Tranche B Agent (the "Agent") to Wachovia Bank,
National Association, One Wachovia Center, 301 South College Street, Charlotte,
North Carolina 28288, or at such other address as may be specified in writing by
the Agent to the Borrower, the aggregate unpaid principal amount of Tranche B
Bid Rate Loans made by the Tranche B Lender to the Borrower under the Credit
Agreement, on the dates and in the principal amounts provided in the Credit
Agreement, and to pay interest on the unpaid principal amount of each such
Tranche B Bid Rate Loan, at such office at the rates and on the dates provided
in the Credit Agreement.

         The date, amount, interest rate and maturity date of each Tranche B Bid
Rate Loan made by the Tranche B Lender to the Borrower, and each payment made on
account of the principal thereof, shall be recorded by the Tranche B Lender on
its books and, prior to any transfer of this Note, endorsed by the Tranche B
Lender on the schedule attached hereto or any continuation thereof, PROVIDED
that the failure of the Tranche B Lender to make any such recordation or
endorsement shall not affect the obligations of the Borrower to make a payment
when due of any amount owing under the Credit Agreement or hereunder in respect
of the Tranche B Bid Rate Loans made by the Tranche B Lender.

         This Note is one of the Tranche B Bid Rate Notes referred to in the
Credit Agreement dated as of April 30, 2001 (as amended, restated, supplemented
or otherwise modified from time to time, the "Credit Agreement"), by and among
the Borrower, the financial institutions party thereto and their assignees under
Section 12.5. thereof, the Agent, and the other parties thereto, and evidences
Tranche B Bid Rate Loans made by the Tranche B Lender thereunder. Terms used but
not otherwise defined in this Note have the respective meanings assigned to them
in the Credit Agreement.

         The Credit Agreement provides for the acceleration of the maturity of
this Note upon the occurrence of certain events and for prepayments of Tranche B
Bid Rate Loans upon the terms and conditions specified therein.

         Except as permitted by Section 12.5. of the Credit Agreement, this Note
may not be assigned by the Tranche B Lender to any Person.

         This Note shall be governed by, and construed in accordance with, the
laws of the State of NEW YORK APPLICABLE TO CONTRACTS EXECUTED, AND TO BE FULLY
PERFORMED, IN SUCH STATE.

         The Borrower hereby waives presentment for payment, demand, notice of
demand, notice of non-payment, protest, notice of protest and all other similar
notices.

<PAGE>

         Time is of the essence for this Note.

         IN WITNESS WHEREOF, the undersigned has executed and delivered this
Tranche B Bid Rate Note under seal as of the date first written above.

                             HRPT PROPERTIES TRUST

                             By:
                                 -----------------------------------------------
                                 Name:
                                      ------------------------------------------
                                 Title:
                                       -----------------------------------------

                                      S-2

<PAGE>

                      SCHEDULE OF TRANCHE B BID RATE LOANS

                  This Note evidences Tranche B Bid Rate Loans made under the
within-described Credit Agreement to the Borrower, on the dates, in the
principal amounts, bearing interest at the rates and maturing on the dates set
forth below, subject to the payments and prepayments of principal set forth
below:

<TABLE>
<CAPTION>
           PRINCIPAL               MATURITY     AMOUNT      UNPAID
DATE OF    AMOUNT OF   INTEREST     DATE OF     PAID OR    PRINCIPAL    NOTATION
 LOAN         LOAN       RATE        LOAN       PREPAID     AMOUNT      MADE BY
-------    ---------   --------    --------     -------    ---------    --------
<S>        <C>         <C>         <C>          <C>        <C>          <C>
</TABLE>

                                       S-3

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00046-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00046-of-00352.parquet"}]]