Exhibit 99.1



                            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 United States Steel Corporation
(the "Corporation") 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"),
I, Thomas J. Usher, Chairman of the Board of Directors and Chief Executive
Officer of the Corporation, certify, 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 results of operations
          of the Corporation.


      By /s/ Thomas J. Usher
         -------------------
          Thomas J. Usher
          Chairman of the Board of Directors
          and Chief Executive Officer


May 12, 2003

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