EXHIBIT 99.2 Certificate Pursuant to Section 1350 of Chapter 63 of Title 18 of the United States Code I, Michael J. Cloherty, the chief financial officer of Arthur J. Gallagher & Co., certify that (i) the Quarterly Report on Form 10-Q of Arthur J. Gallagher & Co. for the quarterly period ended June 30, 2002 (the "Form 10-Q") fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and (ii) the information contained in the Form 10-Q fairly presents, in all material respects, the financial condition and results of operations of Arthur J. Gallagher & Co. and its subsidiaries. /s/ Michael J. Cloherty ----------------------- Michael J. Cloherty August 14, 2002