Exhibit 99.2 KERR-McGEE CORPORATION Kerr-McGee Center Oklahoma City, Oklahoma 73125 CERTIFICATION OF CHIEF FINANCIAL OFFICER REGARDING PERIODIC REPORT CONTAINING FINANCIAL STATEMENTS I, Robert M. Wohleber, the Chief Financial Officer of Kerr-McGee Corporation (the "Issuer"), in compliance with 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, hereby certify in connection with the Issuer's Quarterly Report on Form 10-Q for the period that ended June 30, 2002 as filed with the Securities and Exchange Commission (the "Report") that: * the Report fully complies with the requirements of Section 13(a) or of the Securities Exchange Act of 1934; and * information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Issuer. /s/ Robert M. Wohleber ---------------------- Robert M. Wohleber Chief Financial Officer August 9, 2002