Exhibit 99.1

                                VERTICALNET, INC.
                  CERTIFICATION BY THE CHIEF EXECUTIVE OFFICER
          RELATING TO A PERIODIC REPORT CONTAINING FINANCIAL STATEMENTS

I, Nathanael V. Lentz, President and Chief Executive Officer of Verticalnet,
Inc., a Pennsylvania corporation (the "Company"), hereby certify that:

     (1)  The Company's periodic report on Form 10-Q for the period ended March
          31, 2003 (the "Form 10-Q") fully complies with the requirements of
          Section 13(a) of the Securities Exchange Act of 1934, as amended; and

     (2)  The information contained in the Form 10-Q fairly presents, in all
          material respects, the financial condition and results of operations
          of the Company.


                                           /s/ Nathanael V. Lentz
                                           -------------------------------------
                                           Nathanael V. Lentz
                                           President and Chief Executive Officer
                                           Date: May 15, 2003

A signed original of this written statement required by Section 906 has been
provided to Verticalnet, Inc. and will be retained by Verticalnet, Inc. and
furnished to the Securities and Exchange Commission or its staff upon request.