Exhibit 99.1
                                                                     (Form 10-K)



                            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
("Citizens") on Form 10-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 Section 13(a) 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 Citizens.


Dated: March 31, 2003


                                    /s/ William R. Hartman
                                    --------------------------------------------
                                    William R. Hartman
                                    Chairman, President and Chief Executive
                                    Officer


A signed original or 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.