Exhibit 10.12

                       FIRST AMENDMENT TO AMENDED AND RESTATED
                           AGREEMENT OF LIMITED PARTNERSHIP
                                          OF
                        BRANDYWINE OPERATING PARTNERSHIP, L.P.
                                           

         THIS FIRST AMENDMENT, dated as of December 11, 1997 (the "Amendment"),
amends the Amended and Restated Partnership Agreement (the "Partnership
Agreement") of BRANDYWINE OPERATING PARTNERSHIP, L.P., a Delaware limited
partnership (the "Partnership").  Capitalized terms used herein but not defined
herein shall have the meanings given such terms in the Partnership Agreement.

                                      BACKGROUND

    A.   Pursuant to the Partnership Agreement, Brandywine Realty Trust (the
"General Partner"), as the general partner of the Partnership, has the power and
authority to issue additional Partnership Interests to persons on such terms and
conditions as the General Partner may deem appropriate.

    B.   The General Partner, pursuant to the exercise of such power and
authority and in accordance with the Partnership Agreement, has determined to
execute this Amendment to the Partnership Agreement to evidence the issuance of
additional Partnership Interests and the admission of the other signatories
hereto as Limited Partners of the Partnership in exchange for certain
contributions of real estate and real estate related assets that are being made
to the Partnership on the date hereof pursuant to three separate Agreements
(relating, respectively, to properties commonly known as 1007 Laurel Oak Road,
500 Scarborough Drive and the PaintWorks Property) among the Partnership, the
General Partner and the Admitted Partners.

         NOW, THEREFORE, in consideration of the mutual covenants and
agreements herein contained and other good and valuable consideration, the
receipt, adequacy and sufficiency of which are hereby acknowledged, the parties
hereto, intending to be legally bound, hereby amend the Partnership Agreement as
follows:

         1.   The Partnership Agreement is hereby amended to reflect the
admission as a Limited Partner on the date hereof of the Persons set forth on
Schedule A-1 attached hereto (the "Initial Admitted Partners") and the ownership
by such Persons of the number of Class A Units listed opposite each Person's
name on Schedule A-1.  Immediately following the issuance of such Class A Units
to the Initial Admitted Partners, the Initial Admitted Partners will transfer
all of such Class A Units to the members or partners of such Initial Admitted
Partners, with the result that the Initial Admitted Partners will have withdrawn
from and ceased to be Limited Partners and the Persons listed on Schedule A-2
attached hereto (the "Subsequent Admitted Partners") will have become Limited
Partners and will hold the Class A Units issued pursuant to this Amendment. 
Attached as Schedule B is a list of the Partners of the Partnership prior to the
admission of the Initial Admitted Partners, together with the number and class
of Partnership Interests owned by such partners.  

                                           


         2.   The Partnership Interests issued hereby shall constitute Class A
Units; provided that any distribution to be received by the Subsequent Admitted
Partners on the Class A Units transferred to them on the date hereof  by the
Initial Admitted partners on account of the fiscal quarter in which the 
Subsequent Admitted Partners are admitted to the Partnership shall be pro-rated
to reflect the portion of the fiscal quarter of the Partnership for which the
Subsequent Admitted Partners held such Class A Units and shall not be pro-rata
in accordance with their then Percentage Interests.

         3.   By execution of this Amendment to the Partnership Agreement by
the General Partner and the Initial Admitted Partners and Subsequent Admitted
Partners, the Initial Admitted Partners and Subsequent Admitted Partners agree
to be bound by each and every term of the Partnership Agreement as amended from
time to time in accordance with the terms of the Partnership Agreement.  The
General Partner confirms that the provisions in Section 18.1(a) of the
Partnership Agreement shall apply to the Subsequent Admitted Partners
notwithstanding Section 18.7 of the Partnership Agreement.

         4.   On the date of this Amendment, each of the Subsequebt Admitted
Partners shall execute and deliver to Brandywine Realty Trust an Irrevocable
Proxy coupled with an Interest in the form set forth on Exhibit 1 hereto
attached.

         5.   Except as expressly set forth in this Amendment to the
Partnership Agreement, the Partnership Agreement is hereby ratified and
confirmed in each and every respect.

         IN WITNESS WHEREOF, this Amendment to the Partnership Agreement has
been executed and delivered as of the date first above written.

                             GENERAL PARTNER:

                             BRANDYWINE REALTY TRUST

                             By: /s/ Gerard H. Sweeney                          
                                 ---------------------------------------------

                             Its:  President and CEO                            
                                 ---------------------------------------------

                             INITIAL ADMITTED PARTNERS:

                             LAUREL OAK ROAD LLC

                             By: /s/ M. Sean Scarborough                        
                                 ---------------------------------------------

                             Its: Member                                        
                                 ---------------------------------------------

                         [Executions Continued]

                                         -2-



                             ENGLISH CREEK PARTNERS #2, 
                             Limited Partnership

                             By: /s/ R. Randle Scarborough                     
                                 ---------------------------------------------
         
                             Its:  General Partner                             
                                 ---------------------------------------------



                             PWCCW

                             By: Robert K. Scarborough                         
                                 ---------------------------------------------
         
                                                           

                             SUBSEQUENT ADMITTED PARTNERS:

                             /s/ R. Randle Scarborough                          
                             -------------------------------------------------

                             R. Randle Scarborough

                             /s/ M. Sean Scarborough                            
                             -------------------------------------------------
                             M. Sean Scarborough

                             /s/ Steven L. Shapiro                              
                             -------------------------------------------------
                             Steven L. Shapiro

                             /s/ Robert K. Scarborough                          
                             -------------------------------------------------
                             Robert K. Scarborough

                             /s/ Raymond J. Perkins                             
                             -------------------------------------------------
                             Raymond J. Perkins    




                                         -3-



                                   SCHEDULE "A-1"
              INITIAL                            NUMBER OF
              ADMITTED                           PARTNERSHIP
              PARTNERS                           INTERESTS

              Laurel Oak Road LLC                  61,188

              English Creek Partners #2, 
              Limited Partnership                  63,404
    
              PWCCW                               265,384




 


                                   SCHEDULE "A- 2"



SUBSEQUENT                          NUMBER OF
ADMITTED                           PARTNERSHIP
PARTNERS                            INTERESTS


R. Randle Scarborough                59,578


M. Sean Scarborough                  60,576


Steven L. Shapiro                     1,902


Robert K. Scarborough               265,384


Raymond J. Perkins                    2,536

 



                                     SCHEDULE "B"
                                           
                        BRANDYWINE OPERATING PARTNERSHIP, L.P.
                          OUTSTANDING PARTNERSHIP INTERESTS
                               AS OF DECEMBER 11, 1997
                                           

                                          NUMBER OF
                                         PARTNERSHIP
                                          INTERESTS
LIMITED PARTNERS                     (ALL CLASS A UNITS)


Safeguard Scientifics, Inc.                 252,387


The Nichols Company                           2,742


Brian F. Belcher                              7,245


Jack R. Loew                                  1,245


Craig C. Hough                                1,245


Gary C. Bender                                1,434


Werner A. Fricker                             6,830


Brandywine Holdings I, Inc.                       5


Brandywine Realty Trust                     163,399


                                           NUMBER OF
                                          PARTNERSHIP
                                           INTERESTS
GENERAL PARTNER                          (ALL GP UNITS)

Brandywine Realty Trust                    23,172,642

 
                                           


                                      EXHIBIT 1
                                           
                      IRREVOCABLE PROXY COUPLED WITH AN INTEREST
                                           

       KNOWN ALL MEN BY THESE PRESENTS, that the undersigned hereby 
irrevocably constitutes and appoints the General Partner, any Liquidating 
Trustee, and authorized officers and attorneys-in-fact of each, and each of 
those acting singly, in each case with full power of substitution, as its 
true and lawful agent and attorney-in-fact, with full power and authority in 
its name, place and stead to: execute, swear to, acknowledge, deliver, file 
and record in the appropriate public offices (i) all certificates, documents 
and other instruments (including, without limitation, this Agreement and the 
Certificate and all amendments or restatements thereof) that the General 
Partner or the Liquidating Trustee deems appropriate or necessary to form, 
qualify or continue the existence or qualification of the Partnership as a 
limited partnership (or a partnership in which the limited partners have 
limited liability) in the State of Delaware and in all other jurisdictions in 
which the Partnership may conduct business or own property; (ii) all 
instruments that the General Partner deems appropriate or necessary to 
reflect any amendment, change, modification or restatement of this Agreement 
in accordance with its terms; (iii) all conveyances and other instruments or 
documents that the General Partner deems appropriate or necessary to reflect 
the dissolution and liquidation of the Partnership pursuant to the terms of 
this Agreement, including, without limitation, a certificate of cancellation; 
and (iv) all instruments relating to the admission, withdrawal, removal or 
substitution of any Partner pursuant to the provisions of this Agreement, or 
the Capital Contribution of any Partner.  The foregoing power of attorney is 
irrevocable and a power coupled with an interest, in recognition of the fact 
that each of the Partners will be relying upon the power of the General 
Partner to act as contemplated by this Agreement in any filing or other 
action by it on behalf of the Partnership, and it shall survive the death, 
incapacity or incompetency of a Limited Partner to the effect and extent 
permitted by law and the Transfer of all or any portion of such Limited 
Partner's Partnership Units and shall extend to such Limited Partner's heirs, 
distributees, successors, assigns and personal representatives.



     IN WITNESS WHEREOF, the undersigned has executed and delivered this Proxy
on this [        ] day of December, 1997.



                              -----------------------------------------------
                              (To be executed by each person/entity receiving 
                               Partnership Interests at or immediately after  
                              the Closing)