AOC Aon Corp.

A.M. Best Co. has downgraded the financial strength rating (FSR) to B+ (Good) from A- (Excellent) and the issuer credit rating (ICR) to �bbb-� from �a-� of FFG Insurance Company (FFG) (Dallas, TX). The outlook for all ratings is stable. Subsequently, A.M. Best has withdrawn all ratings and assigned a category NR-3 (Rating Procedure Inapplicable) to FFG as it has been effectively in run off since November 30, 2006. The downgrades reflect the deterioration in FFG�s risk-adjusted capitalization as a result of its 2007 operating loss and resultant reduction in statutory surplus. The ratings also consider the unlimited guarantee and indemnification provided by FFG�s parent company, Aon Corporation (Aon) (Chicago, IL) (NYSE: AOC), to Virginia Surety Company, Inc. for the run off of the FFG reserves. For Best�s Ratings, an overview of the rating process and rating methodologies, please visit www.ambest.com/ratings. Founded in 1899, A.M. Best Company is a global full-service credit rating organization dedicated to serving the financial and health care service industries, including insurance companies, banks, hospitals and health care system providers. For more information, visit www.ambest.com.