Aon to Release Earnings and Hold Webcast; Chairman Patrick G. Ryan to Speak at Investor Conference.

Business Editors

CHICAGO--(BUSINESS WIRE)--Jan. 27, 2003

Aon Corporation (NYSE: AOC) plans to release fourth quarter and full year 2002 earnings on Wednesday, February 12, 2003. The earnings release will be available on Aon's web site at www.aon.com.

A webcast conference call will be held at 10:00 a.m. CST on February 12 hosted by chairman and CEO Patrick G. Ryan through Aon's website, www.aon.com. Windows Media Player is required to listen to this webcast. A replay of the webcast will be available shortly after the live call until Wednesday, February 26, 2003.

On Thursday, February 13, 2003 at 2:20 p.m. EST, Mr. Ryan will speak at the Merrill Lynch Global Insurance Investor Conference. Mr. Ryan's presentation can be listened to live by logging onto the Conference website at: http://www.twst.com/econf/mm/merrill9/aoc.html

It should be noted that Mr. Ryan's remarks may contain forward-looking statements. Aon refers you to the Aon Quarterly Report on Form 10-Q for the quarter ended September 30, 2002 for a description of the business environment in which Aon operates and the important factors that may affect its business. Aon is not under any obligation to (and expressly disclaims any such obligations to) update or alter its forward-looking statements whether as a result of new information, future events or otherwise.

Aon Corporation (www.aon.com) is a holding company that is comprised of a family of insurance brokerage, consulting and insurance underwriting subsidiaries.