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 *

FRADIN RUSSELL P	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)
CEO/Chair - Aon Hewitt	
(Last)          (First)          (Middle)

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

10/1/2010		
(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  	10/1/2010  	 	A	  	27114  	A	  (1)	27114  	D  	 	
Common Stock  	10/1/2010  	 	A	  	35453   (4)	A	  (2)	62567  	D  	 	
Common Stock  	10/1/2010  	 	A	  	50663   (4)	A	  (3)	113230  	D  	 	
Common Stock  	10/1/2010  	 	A	  	127291  	A	  (5)	240521  	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)  	  (6)	10/1/2010  	 	A  	  	50917   	  	10/1/2012   (7)	10/1/2015   (7)	Common Stock  	50917  	$0  	50917  	D  	 	
Employee Stock Option (Right to Buy)  	$29.15  	10/1/2010  	 	A  	  	149613   	  	  (8)	12/3/2017  	Common Stock  	149613  	  (9)	149613  	D  	 	
Employee Stock Option (Right to Buy)  	$20.44  	10/1/2010  	 	A  	  	271320   	  	  (8)	12/1/2018  	Common Stock  	271320  	  (9)	271320  	D  	 	
Employee Stock Option (Right to Buy)  	$17.65  	10/1/2010  	 	A  	  	193800   	  	  (8)	2/15/2015  	Common Stock  	193800  	  (9)	193800  	D  	 	
Employee Stock Option (Right to Buy)  	$31.99  	10/1/2010  	 	A  	  	147006   	  	  (8)	12/1/2019  	Common Stock  	147006  	  (9)	147006  	D  	 	
Employee Stock Option (Right to Buy)  	$17.65  	10/1/2010  	 	A  	  	234627   	  	  (8)	9/5/2016  	Common Stock  	234627  	  (9)	234627  	D  	 	

Explanation of Responses:	
(  1) 	Received pursuant to the Agreement and Plan of Merger, dated as of July 11, 2010, among Aon Corporation ("Aon"), Alps Merger Corp., Alps Merger LLC and Hewitt Associates, Inc. (the "Merger Agreement") in exchange for 42,620 shares of Hewitt common stock held directly. On the effective date of the merger, the closing price of Aon's common stock was $39.28.	
(  2) 	Received pursuant to the Merger Agreement in exchange for 55,727 shares of Hewitt common stock resulting from the settlement of Hewitt restricted stock units. On the effective date of the merger, the closing price of Aon's common stock was $39.28.	
(  3) 	Received pursuant to the Merger Agreement in exchange for 79,634 shares of Hewitt common stock resulting from the settlement of Hewitt performance share units. On the effective date of the merger, the closing price of Aon's common stock was $39.28.	
(  4) 	Current estimate based on anticipated tax withholding.	
(  5) 	Represents a fully vested restricted stock unit award that will be distributed upon the reporting person's departure from Aon. Received pursuant to the Employment Agreement dated as of September 30, 2010 between Aon Corporation and Russell P. Fradin.	
(  6) 	The restricted stock unit award will convert to shares of Aon common stock on a 1-for-1 basis.	
(  7) 	Restricted stock units will vest in accordance with the Aon Stock Incentive Plan as follows: 25% of the shares will vest on each of the second through fifth anniversaries of the date of grant.	
(  8) 	Represents an option to purchase shares of Hewitt common stock that was converted to an option to purchase shares of Aon common stock pursuant to the Merger Agreement. The option is fully vested and immediately exercisable.	
(  9) 	Represents a stock option granted pursuant to the Aon Stock Incentive Plan.	

Reporting Owners	
Reporting Owner Name / Address	Relationships	
	Director	10% Owner	Officer	Other	
FRADIN RUSSELL P
AON CORPORATION - CORPORATE LAW DEPT
200 EAST RANDOLPH STREET, 8TH FLOOR
CHICAGO, IL 60601			CEO/Chair - Aon Hewitt		

Signatures		
/s/ Jennifer L. Kraft - by Jennifer L. Kraft pursuant to a power of attorney from Russell P. Fradin		10/5/2010	
** 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).	
Note:	File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.	
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