OMAHA, NEB. (September 12, 2011) – Aon Risk Solutions, the global risk management business of Aon Corporation (NYSE: AON), today announced Dennis J. Pfeffer has been appointed senior vice president and resident sales director for the Omaha office.

Pfeffer is responsible for business development as well as providing thoughtful and customized risk management advice to Aon clients. He has a vast amount of experience in the design of both traditional and alternative risk management programs, with a focus on health and benefits, property and casualty, group captives and executive liability programs.

Prior to joining Aon, Pfeffer served as a senior vice president at Marsh where he was responsible for business development and client service in Nebraska and Eastern Iowa.

Pfeffer earned Bachelor of Science and Arts degrees in accounting and management from the University of Nebraska – Lincoln. He is a Certified Public Accountant (inactive status) and earned his Associate in Risk Management designation. Pfeffer is a member of the Nebraska Society of CPAs, the Exchange Club of Omaha and serves on the board of directors of Omaha Crime Stoppers. He is also active in the local chapter of Financial Executives International.

Media Contacts:

Kelly Drinkwine                   Cybil Rose            

312.381.2684                      312.755.3537

kelly.drinkwine@aon.com   cybil.rose@kemperlesnik.com

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About Aon

Aon Corporation (NYSE:AON) is the leading global provider of risk management services, insurance and reinsurance brokerage, and human resources solutions and outsourcing. Through its more than 60,000 colleagues worldwide, Aon unites to deliver 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 in over 120 countries. Named the world's best broker by Euromoney magazine's 2008, 2009 and 2010 Insurance Survey, Aon also ranked highest on Business Insurance's listing of the world's insurance brokers based on commercial retail, wholesale, reinsurance and personal lines brokerage revenues in 2008 and 2009. A.M. Best deemed Aon the number one insurance broker based on revenues in 2007, 2008 and 2009, and Aon was voted best insurance intermediary 2007-2010, best reinsurance intermediary 2006-2010, best captives manager 2009-2010, and best employee benefits consulting firm 2007-2009 by the readers of Business Insurance. Visit http://www.aon.com for more information on Aon and http://www.aon.com/manchesterunited to learn about Aon's global partnership and shirt sponsorship with Manchester United.

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