CHICAGO, April 3, 2008 — Aon (Bermuda) Ltd., a unit of Aon Corporation (NYSE: AOC), has promoted Michael G. Merlo, 36, to executive vice president from senior vice president, responsible for strategy and business development. Mr. Merlo will continue to serve as Aon (Bermuda) Ltd.’s chief counsel. He joined the company in 2004.

Mr. Merlo's responsibilities include strategic initiatives relating to enhancing operations, improving client service, developing new business, and optimizing corporate structure. In addition, Mr. Merlo manages Aon (Bermuda) Ltd.'s legal and compliance affairs, and also provides counsel and advocacy to Aon's clients on a wide range of issues. Mr. Merlo also oversees Aon (Bermuda) Ltd.'s claims team, whose personnel assist clients in presentation of claims to Bermuda carriers and resolution of the same.

Prior to joining Aon (Bermuda) Ltd., Mr. Merlo practiced law in the United States for several years, most recently in the Chicago office of the international law firm Lovells. Mr. Merlo’s law practice focused on complex civil litigation, with a particular emphasis on insurance and reinsurance matters.

Mr. Merlo holds a bachelor of science degree from the University of Illinois and a juris doctor degree from the Northwestern University School of Law.

Aon Corporation (NYSE:AOC) is the leading global provider of risk management services, insurance and reinsurance brokerage, and human capital and management consulting. Through its 37,000 professionals worldwide, Aon readily delivers distinctive client value via innovative and effective risk management and workforce productivity solutions. Our industry-leading global resources, technical expertise and industry knowledge are delivered locally through more than 500 offices in more than 120 countries. Aon was ranked by A.M. Best as the number one global insurance brokerage in 2007 based on brokerage revenues, and voted best insurance intermediary, best reinsurance intermediary, and best employee benefits consulting firm in 2007 by the readers of Business Insurance. For more information on Aon, log onto www.aon.com.

Contact: Rahsaan Johnson, 312.381.2684, or David Prosperi, 312.381.2485.