EXHIBIT 99.1 CERTIFICATION OF CHIEF EXECUTIVE OFFICER PURSUANT TO 18 U.S.C. SECTION 1350 AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 Pursuant to 18 U.S.C. Section 1350 as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, I, the undersigned Chief Executive Officer of Thomas & Betts Corporation (the "Company"), hereby certify that the Quarterly Report on Form 10-Q of the Company for the quarterly period ended June 30, 2002 (the "Report") fully complies with the requirements of Section 13(a) of the Securities Exchange Act of 1934 and that information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company. Dated this 12th day of August, 2002. /s/ T. Kevin Dunnigan ----------------------------------------------- T. Kevin Dunnigan Chairman, President and Chief Executive Officer