8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the
Securities Exchange Act of 1934

Date of report (Date of earliest event reported): July 18, 2008

Aon Corporation
(Exact Name of Registrant as Specified in Charter)

Delaware	1-7933	36-3051915
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(IRS Employer Identification No.)

200 East Randolph Street, Chicago, Illinois
(Address of Principal Executive Offices) 60601
(Zip Code)

Registrant's telephone number, including area code: (312) 381-1000

Not Applicable
(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): 

oWritten communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

oSoliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

oPre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

oPre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 8.01.  Other Events.

On July 18, 2008, Aon Corporation (the “Company”) issued a press release announcing that the Company’s Board of Directors has elected Lester B. Knight to serve as Non-Executive Chairman of the Board of Directors effective upon the retirement of Patrick G. Ryan as a Director and Executive Chairman on August 1, 2008.

A copy of the Press Release is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

Item 9.01. Financial Statements and Exhibits.

(a)—(c)    Not applicable.

(d)            Exhibits:

Exhibit Number	Description of Exhibit
99.1	Press Release issued by the Company on July 18, 2008.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	Aon CORPORATION
	By:	/s/ D. Cameron Findlay
Date: July 22, 2008		D. Cameron Findlay
		Executive Vice President and General Counsel

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EXHIBIT INDEX

Exhibit Number	Description of Exhibit
99.1	Press Release issued by the Company on July 18, 2008.

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EX-99.1

Exhibit 99.1

Aon Names Lester B. Knight as non-Executive Chairman

CHICAGO, July 18 - - -  Lester B. Knight, an independent director since 1999, has been elected non-Executive Chairman of the Board of Aon Corporation (NYSE:AOC).  Knight, 50, succeeds Patrick G. Ryan, Aon’s Executive Chairman and founder, who previously announced his intention to retire on August 1, 2008.  Aon is the world’s largest insurance and reinsurance intermediary, and a global leader in human capital consulting.

Knight is a founding and managing partner of RoundTable Healthcare Partners, a healthcare-focused private equity investment firm.  Prior to RoundTable, he was the Chairman and CEO of Allegiance Corporation.  In addition, Knight serves as a Trustee of Northwestern University, and as a director of Evanston Northwestern Healthcare and Junior Achievement of Chicago.

Andy McKenna, Aon’s lead director and chair of the ad hoc Nominating Committee, commented, “Aon’s choice of an independent non-Executive Chairman is consistent with best governance practices of leading global firms.  The Aon family and our shareholders should be confident in Lester’s ability to sustain the independent oversight of their interests.”

Ryan noted, “As I have remarked many times since announcing my retirement earlier this year, Aon is extremely well-positioned for growth and success under the leadership of Greg Case and his management team.  Our Board has never been more excited about the future of Aon.  Lester is a wonderful choice and will ensure continued close collaboration between the Board and management.”

Knight said, “I am gratified to serve Aon’s shareholders in a new capacity and want to thank Pat, Andy and the Board for honoring me with this opportunity.  I look forward to working with the Board, Greg and the management team to ensure Aon continues to strengthen and extend its position of global market leadership.”

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 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 and 2008 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 http://www.aon.com.

Investor Contact:	Media Contact:
Scott Malchow	David Prosperi
Vice President, Investor Relations	Vice President, Global Public Relations
312-381-3983	312-381-2485