Aon Responds to Speculation in Subscription Newsletter.

Business Editors

Aon Corporation (NYSE:AOC) stated today that it is not aware of any formal or informal investigation being conducted by the SEC's Division of Enforcement despite speculation to that effect in a subscription newsletter dated July 10, 2002.

Aon has received a comment letter from the SEC's Division of Corporation Finance dated July 3, 2002 addressing financial statements and related disclosures in Aon's 2001 Form 10-K and first quarter 2002 Form 10-Q. Aon will reply shortly to the SEC's letter.

Aon will report second quarter 2002 earnings in early August and host its investor conference call on the same day. Details will be provided soon.

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

This press release may contain certain statements relating to future results, which are forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995. These forward-looking statements are subject to certain risks and uncertainties that could cause actual results to differ materially from either historical or anticipated results, depending on a variety of factors. Potential factors that could impact results include the general economic conditions in different countries around the world, fluctuations in global equity and fixed income markets, changes in commercial property and casualty premium rates, the competitive environment, the actual cost of resolution of contingent liabilities and other loss contingencies, the final execution of the business transformation plan, the ultimate cost and timing of the implementation thereof, the actual cost savings and other benefits resulting therefrom, whether the Company ultimately implements the proposed spin-off of its underwriting operations, rating agency actions, any proposed capital raising and the timing and terms associated therewith, and events surrounding terrorists attacks of September 11, 2001, including the timing and resolution of related insurance and reinsurance issues. Further information concerning the Company and its business, including factors that potentially could materially affect the Company's financial results, are contained in the Company's filings with the Securities and Exchange Commission.