Aon to Webcast Annual Shareholders' Meeting

CHICAGO, May 11 /PRNewswire-FirstCall/ -- Aon Corporation (NYSE: AOC)
Chairman, Lester B. Knight will host the Company's Annual Shareholders'
Meeting on Friday, May 15, 2009 at 10:00 a.m. Central Time. A webcast of the
presentation and question-and-answer session with shareholders attending the
meeting in Chicago will be available via the Internet. This listen-only
webcast can be accessed by going to the home page of Aon's web site at
www.aon.com. The webcast will be archived for two weeks.

About Aon
Aon Corporation (NYSE: AOC) is the leading global provider of risk management
services, insurance and reinsurance brokerage, and human capital consulting.
Through its more than 37,000 colleagues worldwide, Aon readily delivers
distinctive client value via innovative and effective risk management and
workforce productivity solutions. Aon's industry-leading global resources and
technical expertise are delivered locally through more than 500 offices in
more than 120 countries. Named the world's best broker by Euromoney magazine's
2008 and 2009 Insurance Survey, Aon also ranked highest on Business
Insurance's listing of the world's largest insurance brokers based on
commercial retail, wholesale, reinsurance and personal lines brokerage
revenues in 2008. A.M. Best deemed Aon the number one insurance broker based
on brokerage revenues in 2007 and 2008, and Aon was voted best insurance
intermediary, best reinsurance intermediary and best employee benefits
consulting firm in 2007 and 2008 by the readers of Business Insurance. For
more information on Aon, log onto http://www.aon.com/.

Investor Contact:
Scott Malchow
Vice President, Investor Relations
312-381-3983

Media Contact:
David Prosperi
Vice President, Global Public Relations
312-381-2485

SOURCE Aon Corporation

Investors, Scott Malchow, Vice President, Investor Relations, +1-312-381-3983,
or Media, David Prosperi, Vice President, Global Public Relations,
+1-312-381-2485, both of Aon Corporation