FIRST AMENDMENT TO AGREEMENT OF PURCHASE AND SALE
                              PLYMOUTH MEETING MALL

         THIS FIRST AMENDMENT TO AGREEMENT OF PURCHASE AND SALE ("Amendment") is
made and entered into as of the 28th day of April, 2003, by and between PLYMOUTH
MEETING PROPERTY, LLC, a Delaware limited liability company ("Seller"), and PR
PLYMOUTH MEETING LIMITED PARTNERSHIP, a Pennsylvania limited partnership
("Buyer").

                              W I T N E S S E T H:

         WHEREAS, Seller and Buyer are parties to an Agreement of Purchase and
Sale (the "Original Agreement") dated as of March 7, 2003 pursuant to which
Seller has agreed to sell and Buyer has agreed to buy: certain leasehold and fee
interests, buildings and improvements located in Plymouth Township, Montgomery
County, Pennsylvania and forming a part of Plymouth Meeting Mall, as more fully
described in, and pursuant to the terms and conditions of, the Original
Agreement; and

         WHEREAS, Seller and Buyer desire to amend the Original Agreement
pursuant to the terms of this Amendment.

         NOW, THEREFORE, in consideration of the mutual covenants contained
herein, and for good and valuable consideration, the receipt and sufficiency of
which are hereby acknowledged, Seller and Buyer agree as follows:

         1. Defined Terms. Uppercase and defined terms, which are not defined in
this Amendment, shall have the meaning ascribed to such terms in the Original
Agreement. References to Articles and/or Sections shall correspond to Articles
and Sections in the Original Agreement. Any reference in this Amendment to the
Agreement shall mean the Original Agreement as modified by this Amendment.

         2. Satisfaction of certain conditions. Buyer hereby acknowledges that
the contingencies described in sections 7.2 and 7.3 have been satisfied and it
no longer has any rights to terminate the Agreement based on those sections.

         3. Alternate Agreement. Subparagraph (c) of section 3.5 shall be
amended by deleting the words "March 20, 2003" and substituting in their place
the words "May 23, 2003."

         4. Failure to Close. Article IV of the Original Agreement is hereby
deleted in its entirety and the following is substituted in its place.




                                   ARTICLE IV
                                FAILURE TO CLOSE

            4.1   Liquidated Damages.
                  ------------------

                  Buyer and Seller acknowledge that the amount of damages which
            either party may incur as a result of a default hereunder would be
            substantial, but extremely difficult to ascertain. Accordingly,
            Buyer and Seller agree that the amount of "Liquidated Damages" as
            used herein shall equal Six Million Dollars ($6,000,000.00). The
            parties expressly agree that the Liquidated Damages were determined
            by the parties after negotiation, with both side represented by
            counsel, and that such damages are not intended as a penalty but are
            fairly related to the damage that the non defaulting party would
            suffer from the other party's breach of this Agreement.

            4.2   Buyer's Default.
                  ---------------

                  If Seller has complied with all of the covenants and
            conditions contained herein and is ready, willing and able to sell
            and transfer the Property Assets to Buyer in accordance with this
            Agreement and Buyer for any reason fails to consummate this
            Agreement in breach of its obligations to do so, then the parties
            agree that Seller may, by written notice to Buyer, as its sole
            remedy (i) terminate this Agreement and recover from Buyer as
            liquidated damages an amount equal to the Liquidated Damages,
            together with attorney's fees and court costs, if any, incurred by
            Seller in obtaining payment of the Liquidated Damages, or (ii) seek
            specific performance in which event Seller shall be entitled to
            recover from Buyer any attorney's fees and court costs incurred in
            seeking such remedy, provided that if Seller is unable to obtain the
            remedy of specific performance Seller shall not have waived its
            right to the Liquidated Damages by electing to sue for Specific
            Performance. If Seller receives the Deposit, such amount shall be
            credited against the Liquidated Damages.

            4.3   Seller's Default.
                  ----------------

                  If Buyer has complied with all of the covenants and conditions
            contained. herein and is ready, willing and able to pay the Purchas
            Price to Seller and consummate the transactions contemplated
            hereunder in accordance with this Agreement and Seller for any
            reason fails to consummate this Agreement in breach of its
            obligations to do so, Buyer may as its sole remedy either (i)
            terminate this Agreement whereupon Buyer may recover from Seller as
            liquidated damages an amount equal to the Liquidated Damages
            together with attorney's fees and court costs, if any, incurred by
            Buyer in obtaining payment of the Liquidated Damages, or (ii) seek
            specific performance of the Agreement in which event Buyer shall be
            entitled to receive from Seller any attorney's fees and court costs
            incurred in seeking such remedy, provided that if Buyer is unable to
            obtain the remedy of specific performance Buyer shall not have
            waived its right to the Liquidated Damages by electing to sue for
            specific performance.


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            4.4   Disposition of Deposit as the Result of and Lack of
                  Satisfaction of Conditions.
                  ---------------------------------------------------

                  If Seller terminates this Agreement as a result of the lack of
            satisfaction of any one or more of the conditions to Seller's
            obligations set forth in Section 8.1 or elsewhere in this Agreement
            and the lack of satisfaction of a condition is not related to
            Buyer's or Buyer's Affiliates' default hereunder or under the
            Contract between Echelon Mall Joint Venture and Echelon Acquisition
            LLC and PR Echelon Limited Partnership dated March 7, 2003 (as
            amended contemporaneously herewith, the "Echelon Contract"), or
            Buyer terminates this Agreement as a result of the lack of
            satisfaction of any one or more of the conditions to Buyer's
            obligations set forth in Section 8.2 or elsewhere in this Agreement,
            and the lack of satisfaction of a condition is not related to
            Buyer's breach or default hereunder or under the Echelon Contract,
            then the Deposit shall be promptly returned to Buyer.

            4.5   Cross Default.
                  -------------

                  The parties agree that a breach by a party of the Echelon
            Contract shall also be a breach by such party of this Agreement.

         5. Closing Date. Section 5.1 shall be amended by deleting the words
"April 24" and substituting the words "May 30." In addition, both parties each
shall have the right to extend Closing for a period not to exceed ten (10)
business days provided, however, as a condition to either parties' right to
postpone the Closing, (a) the Alternate Agreement and Leasing Agreement shall
have been agreed to in final form and attached to the Agreement by amendment,
and (b) the party extending Closing also shall extend the Closing under the
Echelon Contract for the same number of days.

         6. Mutual Representations and Warranties. Seller and Buyer represent
and warrant to each other respectively that they have the requisite power and
authority to enter into this Amendment; that all necessary and appropriate
approvals, authorizations and other steps have been taken to effect the legality
of this Amendment; that the signatories executiexecuting this Amendment on
behalf of Seller and Buyer have been duly authorized and empowered to execute
this Amendment on behalf of Seller and Buyer, respectively; and that this
Amendment is valid and shall be binding upon and enforceable against Seller and
Buyer and their respective successors and assigns and shall inure to the benefit
of Seller and Buyer and their respective successors and assigns.

         7. Final Agreement. This Amendment and the Original Agreement cover in
full, each and every final agreement of every kind or nature whatsoever between
Seller and Buyer concerning the Property Assets and all preliminary negotiations
and agreements whatsoever of every kind or nature are merged in this Amendment
and the Original Agreement. This Amendment and the Original Agreement cannot be


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changed or modified in any manner other than by written amendment or
modification executed by Seller and Buyer. Except as expressly provided for
herein or where the context requires to conform the terms and conditions of the
Original Agreement to the above, the terms and conditions of the Original
Agreement shall remain unmodified and are hereby ratified and confirmed.

         8. Counterparts. This Amendment may be executed simultaneously or in
two (2) or more counterparts, each of which shall be deemed an original but
which together shall constitute one and the same instrument.

         IN WITNESS WHEREOF the parties hereto have executed this Amendment as
of the date first above written, but intended to be effective as of the
Effective Date.

ATTEST:                             SELLER:

                                    PLYMOUTH MEETING PROPERTY, LLC


M. LUCINDA MOTSKO                    By: ANDREW B. BOLTON
- ---------------------                    ----------------------------------
M. Lucinda Motsko                        Andrew B. Bolton III
Assistant Secretary                      Vice President


                                     BUYER

                                     PR PLYMOUTH MEETING LIMITED PARTNERSHIP,
                                     a Pennsylvania limited partnership

                                     By: PR PLYMOUTH MEETING LLC, its general
                                         partner

                                          By: PREIT Associates, L.P., its sole
                                              member

                                               By: Pennsylvania Real Estate
                                                   Investment Trust, its general
                                                   partner

Witness:

DANIEL J. IZLER                      By: JEFFREY A. LINN
- -----------------------------            ----------------------------------
Daniel J. Izler                          Jeffrey A. Linn,
                                         Executive Vice President


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