Without TRIA, expect a market with severely limited capacity and pricing at a

                        multiple of current rates

               Media Alert: Expert Available for Commentary

  What:      The Terrorism Risk Insurance Act of 2002 (TRIA) was established
             in November, 2002 requiring commercial property & casualty
             insurers to offer terrorism coverage for all lines of business.
             In addition, TRIA called for the federal government to cover
             90 percent of a company's terrorism losses above a company's
             deductible.   Annual losses covered by the program are capped
             at $100 billion.

          (Logo:  http://www.newscom.com/cgi-bin/prnh/20041215/CGW049LOGO )

             As one of Aon's national property syndication group vice
             presidents, Aaron Davis is an expert on the implications of
             TRIA. He disagrees with the Treasury Department's conclusion
             that the federal government should not be involved, saying TRIA
             is essential for a healthy business marketplace.

             According to Davis:
              -- This report may hinder chances for TRIA reauthorization.
              -- The private market cannot operate without some form of
                 terrorism backstop.
              -- At least 80 percent of property markets have adopted
                 terrorism exclusion for risks extending beyond 2005.

  Who:       Aaron Davis is available by contacting Aon Public Relations.
             Davis is responsible for both terrorism and property risk
             program structuring and marketing for Aon's large account
             clients.

  Contact:   Thaddeus Woosley, Aon Public Relations, Chicago   312-381-2446

This press release contains certain statements related to future results, or states our intentions, beliefs and expectations or predictions for the future 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: general economic conditions in different countries in which we do business around the world, changes in global equity and fixed income markets that could affect the return on invested assets, fluctuations in exchange and interest rates that could influence revenue and expense, rating agency actions that could affect our ability to borrow funds, funding of our various pension plans, changes in the competitive environment, changes in commercial property and casualty markets and commercial premium rates that could impact revenues, changes in revenues and earnings due to the elimination of contingent commissions, other uncertainties surrounding a new compensation model, the impact of regulatory investigations brought by state attorneys general and state insurance regulators related to our compensation arrangements with underwriters and related issues, the impact of class actions and individual lawsuits including client class actions, securities class actions, derivative actions, and ERISA class actions, the cost of resolution of other contingent liabilities and loss contingencies, and the difference in ultimate paid claims in our underwriting companies from actuarial estimates. Further information concerning the Company and its business, including factors that potentially could materially affect the Company's financial results, is contained in the Company's filings with the Securities and Exchange Commission.

PRNewswire -- July 5

Photo: http://www.newscom.com/cgi-bin/prnh/20041215/CGW049LOGO
AP Archive: http://photoarchive.ap.org/
PRN Photo Desk, photodesk@prnewswire.com

SOURCE: Aon Corporation

Web site: http://www.aon.com/