FORM 4
[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).         	UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES
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                      	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public
Utility Holding Company Act of 1935 or Section 30(f) of the Investment Company Act of 1940	                      	

1. Name and Address of Reporting Person *

FARMER JEREMY G O	2. Issuer Name and Ticker or Trading Symbol

AON CORP [ AOC ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable)

_____ Director                      _____ 10% Owner
__ X __ Officer (give title below)      _____ Other (specify below)
Senior VP & Head of HR	
(Last)          (First)          (Middle)

AON CORPORATION - CORPORATE LAW DEPT, 200 EAST RANDOLPH STREET, 8TH FLOOR	3. Date of Earliest Transaction (MM/DD/YYYY)

4/30/2010		
(Street)

CHICAGO, IL 60601
(City)        (State)        (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)

 	6. Individual or Joint/Group Filing (Check Applicable Line)

_ X _ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person	

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned	
1.Title of Security
(Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. Code
(Instr. 8)	4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)	5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)	
			Code	V	Amount	(A) or (D)	Price				
Common Stock  	4/30/2010  	 	A	  	1000  	A	  (7)	45758   (5) (6)	D  	 	
Common Stock  	4/30/2010  	 	F (8)	  	395  	D	$42.46  	45363   (5) (6)	D  	 	
Common Stock  	2/17/2011  	 	A (1)	  	17796   (1)	A	  (1)	63159   (6)	D  	 	
Common Stock  	2/17/2011  	 	F (2)	  	5646  	D	$51.92  	57513   (6)	D  	 	

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)	
1. Title of Derivate Security
(Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. Code
(Instr. 8)	5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)	6. Date Exercisable and Expiration Date	7. Title and Amount of Securities Underlying Derivative Security
(Instr. 3 and 4)	8. Price of Derivative Security
(Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)	
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares					
Restricted Stock Unit Award (Right to Receive)  	  (3)	2/17/2011  	 	A  	  	3876   	  	2/17/2012   (4)	2/17/2014  	Common Stock  	3876  	$0  	3876  	D  	 	

Explanation of Responses:	
(  1) 	Represents shares of common stock issued upon the settlement of performance share units originally granted approximately three years ago under the third cycle of the Leadership Performance Program ("LPP3") on March 13, 2008. The number of shares issued was determined by the Organization and Compensation Committee of Aon's Board of Directors on February 17, 2011 based upon Aon's performance relative to a cumulative adjusted three year earnings per share target for the period beginning January 1, 2008 and ending December 31, 2010. In accordance with the terms of LPP3, and the achievement of specified growth targets under LPP3, settlement occurred at 130% of the original target value. The terms of LPP3 are more fully described in a Current Report on Form 8-K filed with the SEC on March 19, 2008, and in the plan document filed as Exhibit 10.3 to Aon's Quarterly Report on Form 10-Q for the quarter ended March 31, 2008 filed with the SEC on May 9, 2008.	
(  2) 	Shares of common stock withheld by the issuer for the payment of withholding taxes in connection with the settlement of a performance share unit award.	
(  3) 	The restricted stock unit award converts to shares of common stock on a 1-for-1 basis.	
(  4) 	The restricted stock unit award will vest in accordance with the terms of the Aon Stock Incentive Plan as follows: 33 1/3% of the awards will vest on each of the first through third anniversaries of the date of grant.	
(  5) 	As a result of an administrative error, the number of shares of Aon common stock beneficially owned by the reporting person was understated in a Form 4 filed with the SEC on June 22, 2010. The number of shares of Aon common stock beneficially owned by the reporting person is accurately reflected in this filing.	
(  6) 	Includes 924 shares held pursuant to the Aon employee stock purchase plan.	
(  7) 	Represents shares of common stock issued upon the vesting of a restricted stock unit award.	
(  8) 	Shares of common stock withheld by the issuer for the payment of withholding taxes in connection with the settlement of a restricted stock unit award.	

Reporting Owners	
Reporting Owner Name / Address	Relationships	
	Director	10% Owner	Officer	Other	
FARMER JEREMY G O
AON CORPORATION - CORPORATE LAW DEPT
200 EAST RANDOLPH STREET, 8TH FLOOR
CHICAGO, IL 60601			Senior VP & Head of HR		

Signatures		
/s/ Jennifer L. Kraft - by Jennifer L. Kraft pursuant to a power of attorney from Jeremy G.O. Farmer		2/22/2011	
** Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.	
*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).	
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).	
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