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 Citizens Banking Corporation Amended and
Restated Section 401(k) Plan (the "Plan") on Form 11-K for the period ending
December 31, 2002 as filed with the Securities and Exchange Commission on the
date hereof (the "Report"), I, William R. Hartman, Chief Executive Officer of
the Company, certify, pursuant to Section 906 of the Sarbanes-Oxley Act of 2002,
18 U.S.C. Section 1350, that:

(1)      The Report fully complies with the requirements of Sections 13(a) and
         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 Plan.


Dated: June 25, 2003


                                                        /s/ William R. Hartman
                                                        ----------------------
                                                            William R. Hartman
                                                       Chief Executive Officer


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.