CHICAGO, IL – July 14, 2008 – Aon Corporation (NYSE: AOC) will report its second quarter results after the market closes on Thursday, July 31, 2008.  The earnings release will be available on Aon’s web site at www.aon.com. 

Gregory C. Case, president and CEO, will host a webcast discussion of the quarter’s results on Friday, August 1, 2008 at 10:00 AM Central Time, which will be broadcast live through Aon’s website at www.aon.com. Windows Media Player is required to listen to this webcast. A replay will be available shortly after the live webcast.

About Aon

Aon Corporation (NYSE:AOC) is the leading global provider of risk management services, insurance and reinsurance brokerage, human capital and management consulting. Through its 36,000 colleagues 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 named the world’s “best broker” by Euromoney magazine’s 2008 Insurance Survey. Aon also 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.

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Investor Contact:                                Media Contact:

Scott Malchow                                   David Prosperi

Vice President, Investor Relations        Vice President, Global Public Relations

312-381-3983                                     312-381-2485