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                                                                    EXHIBIT 99.1

                  CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER
           PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002
            AND SECURITIES AND EXCHANGE COMMISSION RELEASE 34-46427

    I, Jeffrey E. Kelter, the principal executive officer of Keystone Property
Trust, certify that:

    1.  I have reviewed our 2002 Annual Report on Form 10-K of Keystone Property
       Trust;

    2.  Based on my knowledge, this report does not contain any untrue statement
       of a material fact or omit to state a material fact necessary to make the
       statements made, in light of the circumstances under which such
       statements were made, not misleading with respect to the period covered
       by the report;

    3.  Based on my knowledge, the financial statements, and other financial
       information included in this report, fairly present in all material
       respects the financial condition, results of operations and cash flows of
       the registrant as of, and for, the periods presented in this report;

    4.  The registrant's other certifying officer and I are responsible for
       establishing and maintaining disclosure controls and procedures (as
       defined in Exchange Act Rules 13a-14 and 15d-14) for the registrant and
       we have:

       a.  designed such disclosure controls and procedures to ensure that
           material information relating to the registrant, including its
           consolidated subsidiaries, is made known to us by others within those
           entities, particularly during the period in which this report is
           being prepared;

       b.  evaluated the effectiveness of the registrant's disclosure controls
           and procedures as of a date within 90 days prior to the filing date
           of this report (the "Evaluation Date"); and

       c.  presented in this report our conclusions about the effectiveness of
           the disclosure controls and procedures based on our evaluation as of
           the Evaluation Date;

    5.  The registrant's other certifying officer and I have disclosed, based on
       our most recent evaluation, to the registrant's auditors and the audit
       committee of registrant's board of trustees:

       a.  all significant deficiencies in the design or operation of internal
           controls which could adversely affect the registrant's ability to
           record, process, summarize and report financial data and have
           identified for the registrant's auditors any material weaknesses in
           internal controls; and

       b.  any fraud, whether or not material, that involves management or other
           employees who have a significant role in the registrant's internal
           controls; and

    6.  The registrant's other certifying officer and I have indicated in this
       report whether or not there were significant changes in internal controls
       or in other factors that could significantly affect internal controls
       subsequent to the date of our most recent evaluation, including any
       corrective actions with regard to significant deficiencies and material
       weaknesses.

Date: March 27, 2003

                                  /s/ Jeffrey E. Kelter
                                  President & Chief Executive Officer