Document:

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                                                                   Exhibit 10.51

                    THIRD AMENDMENT TO RESTRICTED SHARE AWARD

     This Third Amendment to Restricted Share Award is dated December 17, 1999
by and between Brandywine Realty Trust, a Maryland real estate investment trust
(the "Company") and Anthony A. Nichols, Sr. ("Grantee").

     WHEREAS, the Company and Grantee desire to amend the Restricted Share Award
dated January 2, 1998, as previously amended pursuant to a First Amendment dated
October 31, 1998 and a Second Amendment dated March 19, 1999 (the "Award")
between the Company and the Grantee as provided herein.

     NOW, THEREFORE, the parties hereto, intending to be legally bound hereby,
agree as follows:

          1. Paragraph 4(b) of the Award is amended and restated in its entirety
     to read as follows:

               Subject to Paragraph 4(a), a Vesting Date for Restricted Shares
               subject to the Award shall occur in accordance with the following
               schedule:

               (i) As to twelve and one-half percent (12.5%) of the Restricted
          Shares, December 31, 1999;

               (ii) As to an additional twelve and one-half percent (12.5%) of
          the Restricted Shares, January 2, 2000;

               (iii) As to an additional twenty five percent (25%) of the
          Restricted Shares, January 2, 2001;

               (iv) As to an additional twenty five percent (25%) of the
          Restricted Shares, January 2, 2002;

               (v) As to an additional twenty five percent (25%) of the
          Restricted Shares, January 2, 2003.

          2. This Third Amendment does not amend the Award in any respect except
     as set forth above, and the Award, as amended hereby, shall continue in
     full force and effect after the date hereof in accordance with its terms.

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     IN WITNESS WHEREOF, the parties have executed this Third Amendment the day
and year first above written.

                                    BRANDYWINE REALTY TRUST

                                    By:
                                       -----------------------------------------
                                    Title: President and Chief Executive Officer

                                   -----------------------------------------
                                             Anthony A. Nichols, Sr.

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                                                                   Exhibit 10.52

                    THIRD AMENDMENT TO RESTRICTED SHARE AWARD

     This Third Amendment to Restricted Share Award is dated December 17, 1999
by and between Brandywine Realty Trust, a Maryland real estate investment trust
(the "Company") and Gerard H. Sweeney ("Grantee").

     WHEREAS, the Company and Grantee desire to amend the Restricted Share Award
dated January 2, 1998, as previously amended pursuant to a First Amendment dated
October 31, 1998 and a Second Amendment dated March 19, 1999(the "Award"),
between the Company and the Grantee as provided herein.

     NOW, THEREFORE, the parties hereto, intending to be legally bound hereby,
agree as follows:

          1. Paragraph 4(b) of the Award is amended and restated in its entirety
     to read as follows:

               Subject to Paragraph 4(a), a Vesting Date for Restricted Shares
               subject to the Award shall occur in accordance with the following
               schedule:

               (i) As to twelve and one-half percent (12.5%) of the Restricted
          Shares, December 31, 1999;

               (ii) As to an additional twelve and one-half percent (12.5%) of
          the Restricted Shares, January 2, 2000;

               (iii) As to an additional twenty five percent (25%) of the
          Restricted Shares, January 2, 2001;

               (iv) As to an additional twenty five percent (25%) of the
          Restricted Shares, January 2, 2002;

               (v) As to an additional twenty five percent (25%) of the
          Restricted Shares, January 2, 2003.

     2. This Third Amendment does not amend the Award in any respect except as
set forth above, and the Award, as amended hereby, shall continue in full force
and effect after the date hereof in accordance with its terms.

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     IN WITNESS WHEREOF, the parties have executed this Third Amendment the day
and year first above written.

                                    BRANDYWINE REALTY TRUST

                                    By:
                                       -----------------------------------------
                                    Title: President and Chief Executive Officer

                                    -----------------------------------------
                                               Gerard H. Sweeney<PAGE>

                                                                   Exhibit 10.53

                 BRANDYWINE REALTY TRUST RESTRICTED SHARE AWARD

     This is a Restricted Share Award dated May 18, 1999 from Brandywine Realty
Trust, a Maryland real estate investment trust (the "Company") to Jeffrey F.
Rogatz ("Grantee"). Terms used herein as defined terms and not defined herein
have the meanings assigned to them in the Brandywine Realty Trust 1997 Long-Term
Incentive Plan, as amended from time to time (the "Plan").

     1. DEFINITIONS. As used herein:

          (a) "AWARD" means the award of Restricted Shares hereby granted.

          (b) "BOARD" means the Board of Trustees of the Company, as constituted
     from time to time.

          (c) "CAUSE" means "Cause" as defined in the Plan.

          (d) "CHANGE OF CONTROL" means "Change of Control" as defined in the
     Plan.

          (e) "CODE" means the Internal Revenue Code of 1986, as amended from
     time to time, and any successor thereto.

          (f) "COMMITTEE" means the Committee appointed by the Board in
     accordance with Section 2 of the Plan, if one is appointed and in existence
     at the time of reference. If no committee has been appointed pursuant to
     Section 2, or if such a committee is not in existence at the time of
     reference, "Committee" means the Board.

          (g) "DATE OF GRANT" means May 18, 1999, the date on which the Company
     awarded the Restricted Shares.

          (h) "EMPLOYER" means the Company or the Subsidiary for which Grantee
     is performing services on the applicable Vesting Date.

          (i) "RESTRICTED PERIOD" means, with respect to each Restricted Share,
     the period beginning on the Date of Grant and ending on the Vesting Date.

          (j) "RESTRICTED SHARES" means the 13,201 Shares which are the subject
     of the Award hereby granted.

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          (k) "RULE 16B-3" means Rule 16b-3 promulgated under the 1934 Act, as
     in effect from time to time.

          (l) "SHARE" means a common share of beneficial interest, $.01 par
     value per share, of the Company, subject to substitution or adjustment as
     provided in Section 3(c) of the Plan.

          (m) "SUBSIDIARY" means, with respect to the Company or parent, a
     subsidiary company, whether now or hereafter existing, as defined in
     section 424(f) of the Code, and any other entity 50% or more of the
     economic interests in which are owned, directly or indirectly, by the
     Company.

          (n) "VESTING DATE" means the date on which the restrictions imposed
     under Paragraph 3 on a Restricted Share lapse, as provided in Paragraph 4.

     2. GRANT OF RESTRICTED SHARES. Subject to the terms and conditions set
forth herein and in the Plan, the Company hereby grants to Grantee the
Restricted Shares. Grantee shall pay to the Company $.01 per Restricted Share
granted to him.

     3. RESTRICTIONS ON RESTRICTED SHARE. Subject to the terms and conditions
set forth herein and in the Plan, prior to the Vesting Date in respect of
Restricted Shares, Grantee shall not be permitted to sell, transfer, pledge or
assign such Restricted Shares. Share certificates evidencing Restricted Shares
shall be held in custody by the Company until the restrictions thereon have
lapsed. Concurrently herewith, Participant shall deliver to the Company a share
power, endorsed in blank, relating to the Restricted Shares covered by the
Award. During the Restricted Period, share certificates evidencing Restricted
Shares shall bear a legend in substantially the following form:

     THE TRANSFERABILITY OF THIS CERTIFICATE AND THE SHARES REPRESENTED HEREBY
     ARE SUBJECT TO THE TERMS AND CONDITIONS (INCLUDING FORFEITURE) OF THE
     BRANDYWINE REALTY TRUST 1997 LONG-TERM INCENTIVE PLAN AND AN AGREEMENT
     ENTERED INTO BETWEEN THE REGISTERED OWNER AND BRANDYWINE REALTY TRUST.
     COPIES OF SUCH PLAN AND AGREEMENT ARE ON FILE IN THE PRINCIPAL OFFICES OF
     BRANDYWINE REALTY TRUST AND WILL BE MADE AVAILABLE TO ANY SHAREHOLDER
     WITHOUT CHARGE UPON REQUEST TO THE SECRETARY OF THE COMPANY.

     4. LAPSE OF RESTRICTIONS.

          (a) Subject to the terms and conditions set forth herein and in the
     Plan, the restrictions set forth in Paragraph 3 on each Restricted Share
     that has not been forfeited shall

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     lapse on the applicable Vesting Date in respect of such Restricted Share,
     provided that either (i) on the Vesting Date, Grantee is, and has from the
     Date of Grant continuously been, an employee of the Company or a Subsidiary
     during the Restricted Period, or (ii) Grantee's termination of employment
     before the Vesting Date is due to death or disability.

          (b) Subject to Paragraph 4(a), a Vesting Date for Restricted Shares
     subject to the Award shall occur in accordance with the following schedule:

                    (i) As to twenty five percent (25%) of the Restricted
               Shares, January 2, 2000;

                    (ii) As to an additional twenty five percent (25%) of the
               Restricted Shares, January 2, 2001;

                    (iii) As to an additional twenty five percent (25%) of the
               Restricted Shares, January 2, 2002;

                    (iv) As to an additional twenty five percent (25%) of the
               Restricted Shares, January 2, 2003;

          (c) Notwithstanding Paragraph 4(b), a Vesting Date for all Restricted
     Shares subject to the Award shall occur upon the occurrence of a Change of
     Control, and the Restricted Shares, to the extent not previously vested,
     shall thereupon vest in full, provided that (i) as of the date of the
     Change of Control, Grantee is, and has from the Date of Grant continuously
     been, an employee of the Company or a Subsidiary or (ii) Grantee's
     termination of employment before the date of the Change of Control is
     because of death or disability.

     5. FORFEITURE OF RESTRICTED SHARES.

          (a) Subject to the terms and conditions set forth herein, if Grantee
     terminates employment with the Company and all Subsidiaries during the
     Restricted Period for reasons other than as described in Paragraph 4(c),
     Grantee shall forfeit the Restricted Shares which have not vested as of
     such termination of employment, provided that Grantee shall not, on account
     of such termination, forfeit Restricted Shares which have not vested as of
     Grantee's termination of employment with the Employer because of death or
     disability. Upon a forfeiture of the Restricted Shares as provided in this
     Paragraph 5, the Restricted Shares shall be deemed canceled.

          (b) The provisions of this Paragraph 5 shall not apply to Restricted
     Shares as to which the restrictions of Paragraph 3 have lapsed.

     6. RIGHTS OF GRANTEE. During the Restricted Period, with respect to the
Restricted Shares, Grantee shall have all of the rights of a shareholder of the
Company, including the right

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to vote the Restricted Shares and the right to receive any distributions or
dividends payable on Shares.

     7. NOTICES. Any notice to the Company under this Award shall be made to:

                          Brandywine Realty Trust
                          14 Campus Boulevard
                          Newtown Square, PA 19073
                          Attention: Chief Financial Officer

or such other address as may be provided to Grantee by written notice. Any
notice to Grantee under this award shall be made to Grantee at the address
listed in the Company's personnel files. All notices under this Award shall be
deemed to have been given when hand-delivered, telecopied or mailed, first class
postage prepaid, and shall be irrevocable once given.

     8. SECURITIES LAWS. The Committee may from time to time impose any
conditions on the Restricted Shares as it deems necessary or advisable to ensure
that the Plan satisfies the conditions of Rule 16b-3, and that Shares are issued
and resold in compliance with the Securities Act of 1933, as amended.

     9. DELIVERY OF SHARES. Upon a Vesting Date, the Company shall notify
Grantee (or Grantee's legal representatives, estate or heirs, in the event of
Grantee's death before a Vesting Date) that the restrictions on the Restricted
Shares have lapsed. Within ten (10) business days of a Vesting Date, the Company
shall, without payment from Grantee for the Restricted Shares, deliver to
Grantee a certificate for the Restricted Shares without any legend or
restrictions, except for such restrictions as may be imposed by the Committee,
in its sole judgment, under Paragraph 8, provided that no certificates for
Shares will be delivered to Grantee until appropriate arrangements have been
made with Employer for the withholding of any taxes which may be due with
respect to such Shares. The Company may condition delivery of certificates for
Shares upon the prior receipt from Grantee of any undertakings which it may
determine are required to assure that the certificates are being issued in
compliance with federal and state securities laws. The right to payment of any
fractional Shares shall be satisfied in cash, measured by the product of the
fractional amount times the fair market value of a Share on the Vesting Date, as
determined by the Committee.

     10. AWARD NOT TO AFFECT EMPLOYMENT. The Award granted hereunder shall not
confer upon Grantee any right to continue in the employment of the Company or
any Subsidiary.

     11. MISCELLANEOUS.

          (a) The address for Grantee to which notice, demands and other
     communications are to be given or delivered under or by reason of the
     provisions hereof shall be the Grantee's address as reflected in the
     Company's personnel records.

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          (b) This Award and all questions relating to its validity,
     interpretation, performance and enforcement shall be governed by and
     construed in accordance with the laws of Pennsylvania.

                                    BRANDYWINE REALTY TRUST

                                    By:
                                       -----------------------------------------
                                    Title: President and Chief Executive Officer

Accepted:

----------------------------------------
Jeffrey F. Rogatz

                                      -5-

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