<Page>

                                                                    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 Annual Report of United Stationers Inc. and United
Stationers Supply Co. (collectively, the "Company") on Form 10-K for the year
ended December 31, 2002 as filed with the Securities and Exchange Commission on
the date hereof (the "Report"), I, Richard W. Gochnauer, President and Chief
Executive Officer, 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:

     (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.

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

/s/ Richard W. Gochnauer
- ----------------------------------------

Richard W. Gochnauer
President and Chief Executive Officer
March 28, 2003