Ownership Submission
FORM 3
 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
  Dail Baljit
 2. Date of Event Requiring Statement (Month/Day/Year)
05/16/2011		 3. Issuer Name and Ticker or Trading Symbol
AON CORP [AOC]
(Last)
(First)
(Middle)
AON CORPORATION - CORPORATE LAW DEPT, 200 EAST RANDOLPH STREET, 8TH FLOOR		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
CEO-Aon Hewitt
 5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

CHICAGO, IL 60601		 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security
(Instr. 4)		 2. Amount of Securities Beneficially Owned
(Instr. 4)		 3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)		 4. Nature of Indirect Beneficial Ownership
(Instr. 5)
Common Stock 860
D
 

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)		 2. Date Exercisable and Expiration Date
(Month/Day/Year)		 3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)		 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)		 6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Restricted Stock Unit Award (Right to Receive) 02/20/2012 02/20/2012 Common Stock 1,525 (2) $ (1) D  
Restricted Stock Unit Award (Right to Receive) 02/25/2012 02/25/2013 Common Stock 5,692 (3) $ (1) D  
Restricted Stock Unit Award (Right to Receive) 02/17/2012 02/17/2014 Common Stock 6,741 (4) $ (1) D  
Employee Stock Option (Right to Buy)   (5) 03/19/2015 Common Stock 5,137 $ 38.93 D  

Reporting Owners

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

Signatures

/s/ Jennifer L. Kraft - by Jennifer L. Kraft pursuant to a power of attorney from Baljit Dail 05/26/2011
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(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).
(1) The restricted stock unit award will convert to shares of Aon common stock on a 1-for-1 basis.
(2) Of this amount, 1,525 restricted stock units will vest on February 20, 2012.
(3) Of this amount, 2,846 restricted stock units will vest on each of February 25, 2012 and February 25, 2013.
(4) Of this amount, 2,248 restricted stock units will vest on February 17, 2012, 2,247 restricted stock units will vest on February 17, 2013, and 2,246 restricted stock units will vest on February 17, 2014.
(5) Of the shares represented by this option, all of the shares will vest on March 19, 2012.

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