Exhibit 99.3

CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

     In connection with the Quarterly Report of Liberty Property Limited Partnership (the “Company”) on Form 10-Q for the period ended March 31, 2003 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, WILLIAM P. HANKOWSKI, Chief Executive Officer of Liberty Property Trust (the sole general partner of the Company), certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that based on my knowledge:

     (1)  The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

     (2)  The information contained in the Report fairly presents, in all material respects, the financial condition and result of operations of the Company.

/s/ WILLIAM P. HANKOWSKY William P. Hankowsky
Chief Executive Officer of Liberty Property Trust,
the sole general partner of the Company