Exhibit 99.1

                              W. P. CAREY & CO. LLC

                    CERTIFICATION OF CHIEF EXECUTIVE OFFICER
                       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 W. P. Carey & Co. LLC (the "Company")
on Form 10-Q for the period ending March 31, 2003 as filed with the Securities
and Exchange Commission on the date hereof (the "Report"), we, William Polk
Carey, Co-Chief Executive Officer of the Company, and Gordon F. DuGan, Co-Chief
Executive Officer of the Company, certify, to the best of our knowledge and
belief, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906
of the Sarbanes-Oxley Act of 2002, that:

      (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 Polk Carey                  /s/ Gordon F. DuGan
---------------------------------       ----------------------------------------

    William Polk Carey                      Gordon F. DuGan
    Chairman                                President
    (Co-Chief Executive Officer)            (Co-Chief Executive Officer)
     5/13/2003                               5/13/2003
     ---------                               ---------
    Date                                    Date

A signed original of this written statement required by Section 906 has been
provided to W. P. Carey & Co. LLC and will be retained by W. P. Carey & Co. LLC
and furnished to the Securities and Exchange Commission or its staff upon
request.