Exhibit 10.18
                             TAX INDEMNITY AGREEMENT

         This Tax Indemnity Agreement (this "Agreement") is made as of June 2,
2004 by and among PREIT Associates, L.P. ("PALP"), Ivyridge Investment Corp.
("Ivyridge"), Leonard B. Shore, Lewis M. Stone, Pan American Office Investments,
LP ("Pan American Office"), George Rubin, Ronald Rubin, and the Non QTIP Marital
Trust under the will of Richard I. Rubin (the "Trust," and together with
Ivyridge, Pan American Office, Messrs. Shore and Stone, George Rubin, and Ronald
Rubin, the "Limited Partners").

         WHEREAS, reference is made to (i) that certain Call and Put Option
Agreement dated April 28, 2003 by and among PR New Castle LLC (the "General
Partner"), PALP, Ivyridge, and Pan American (the "Option Agreement") and (ii)
that certain Contribution Agreement dated April 22, 2003 by and among PALP,
Ivyridge, Pan American, certain prior limited partners of New Castle Associates,
and Pennsylvania Real Estate Investment Trust (the "Contribution Agreement");
and

         WHEREAS, pursuant to Section 2(a) of the Option Agreement, PALP has
delivered to the Ivyridge and Pan American written notice of its election to
exercise the Call (as defined in the Option Agreement); and

         WHEREAS, PALP is required to deliver this Agreement in connection with
the closing effecting the consummation of the Call.

         NOW, THEREFORE, in consideration of the foregoing, and intending to be
legally bound, the parties hereby agree as follows:

      1. PALP, as the sole member of the General Partner, shall not permit the
         Replacement Property (as defined in the Contribution Agreement) or the
         Retained Interests (as defined in the Option Agreement) to be disposed
         of for a period of eight years following April 28, 2003 (the "Period")
         in such a manner that may cause the Limited Partners to recognize
         taxable income, and if PALP, as the sole member of the General Partner,
         disposes of the Replacement Property or the Retained Interests within
         the Period, such disposition shall be pursuant to a tax-free exchange
         under Section 1031 of the Internal Revenue Code (the "Code") or shall
         otherwise be a tax-free disposition.

      2. Notwithstanding Paragraph 1, PALP, as the sole member of the General
         Partner, may dispose of the Replacement Property or the Retained
         Interests during the Period in a taxable transaction if the Limited
         Partners are paid by PALP an amount sufficient to reimburse each such
         partner for any tax liability resulting from such transfer by reason of
         Section 704(c) of the Code, together with all taxes payable on such
         reimbursement.

      3. PALP shall cooperate in good faith with the Limited Partners in
         executing such documentation as may be required (such as limited
         guarantees of indebtedness by the Limited Partners) to avoid
         recognition of income or gain to such Limited Partners by reason of a
         constructive distribution to them under Section 752 of the Code
         relating to relief from liabilities.






      4. The covenants, terms, and provisions of this Agreement shall be binding
         upon and inure to benefit of the parties hereto and their respective
         heirs, legal representatives, successors, transferees, and assigns.

      5. The laws of the Commonwealth of Pennsylvania shall govern the validity
         of this Agreement, the construction of its terms, and the
         interpretation of the rights and duties of the parties hereto.

      6. This Agreement may be executed in any number of counterparts with the
         same effect as if all of the parties hereto had signed the same
         document and any and all counterparts may be executed by facsimile. All
         counterparts shall be construed together and shall constitute one
         agreement.






















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         IN WITNESS WHEREOF, the parties have executed this Agreement as of the
day first written above.

PREIT ASSOCIATES, L.P.

By:      Pennsylvania Real Estate Investment Trust, its general partner


         By: /s/ Bruce Goldman
            ---------------------------------------------------
            Name: Bruce Goldman
            Title: Executive Vice President and General Counsel

IVYRIDGE INVESTMENT CORP.


By:      /s/ Arthur H. Kaplan
         -----------------------------------------------
         Name:  Arthur H. Kaplan
         Title: President

PAN AMERICAN ASSOCIATES

By:      Pan American Office Investments, L.P., its general partner

         By: Pan American Office Investments - G.P., Inc., its general partner


             By: /s/ Ronald Rubin
                -----------------------------------------------
                Name: Ronald Rubin
                Title: President

PR NEW CASTLE LLC, A PENNSYLVANIA LIMITED LIABILITY COMPANY

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

         By: Pennsylvania Real Estate Investment Trust, its general partner



             By: /s/ Bruce Goldman
                -----------------------------------------------
                Name: Bruce Goldman
                Title: Executive Vice President and General Counsel

RICHARD I. RUBIN & CO.


By:      /s/ Ronald Rubin
   ---------------------------------
Name:  Ronald Rubin
Title: Partner




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LEONARD B. SHORE


/s/ Leonard B. Shore
- --------------------------


LEWIS M. STONE


/s/ Lewis M. Stone
- --------------------------


PAN AMERICAN OFFICE INVESTMENTS, L.P.
  By: Pan American Office Investments - G.P., Inc., its general partner


      By:  /s/ Ronald Rubin
         ----------------------------
         Name: Ronald Rubin
         Title: President

GEORGE RUBIN

/s/ George Rubin
- ---------------------------

RONALD RUBIN


/s/ Ronald Rubin
- ---------------------------


THE NON QTIP MARITAL TRUST
UNDER THE WILL OF RICHARD I. RUBIN


By: /s/ Ronald Rubin
    ------------------------
Name:  Ronald Rubin
Title: Trustee


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