Exhibit 23.1


                      CONSENT OF INDEPENDENT ACCOUNTANTS

   
As independent public accountants, we hereby consent to the incorporation of
our report dated April 27, 1998 in this Form 8-K/A No. 1 on the combined
statement of revenue and certain expenses of the First Commercial Properties
and our report dated May 1, 1998 in this Form 8-K/A No. 1 on the combined
statement of revenue and certain expenses of One Christina Centre into the
Company's previously filed Registration Statements on Forms S-3 (File No.
333-20991, File No. 333-20999, File No. 333-56237, File No. 46647 and File No.
53359) and Forms S-8 (File No. 333-14243, File No. 333-28427, and File No.
52957).
    

                                                           ARTHUR ANDERSEN LLP

Philadelphia, Pa.,
  July 21, 1998