EXHIBIT 99.1 CERTIFICATION OF CHIEF EXECUTIVE OFFICER OF SUMMIT BANCSHARES, INC. This certification is provided pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 and accompanies the quarterly report on Form 10-Q (the "Form 10-Q") for the quarter ended June 30, 2003 of Summit Bancshares, Inc. (the "Issuer"). I, Philip E. Norwood, the Chairman, President, and Chief Executive Officer of the Issuer certify that: (i) the Form 10-Q fully complies with the requirements of section 13(a) or section 15(d) of the Securities Exchange Act of 1934 (U.S.C. 78m(a) or 78o(d)); and (ii) the information contained in the Form 10-Q fairly presents, in all material respects, the financial condition and results of operations of the Issuer. Dated: August 1, 2003 /s/ Philip E. Norwood --------------------------------------- Name: Philip E. Norwood Title: Chairman, President and CEO Subscribed and sworn to before me on this 1st day of August 2003. /s/ Karen S. Appel --------------------------------------- Name: Karen S. Appel Title: Notary Public My commission expires: August 5, 2006 37