FORM 5 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Form 3 Holdings Reported Form 4 Transactions Reported

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ANNUAL STATEMENT OF CHANGES IN 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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1. Name and Address of Reporting Person * RYAN SHIRLEY W 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 _____ Officer (give title below) __X__ Other (specify below) Spouse of Director and Officer (Last) (First) (Middle) C/O AON CORPORATE LAW DEPARTMENT, 8TH FLOOR, 200 EAST RANDOLPH DRIVE 3. Statement for Issuer's Fiscal Year Ended (Month/Day/Year) 12/31/2005 (Street) CHICAGO, IL 60601 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Reporting (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 Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned at end of Issuer's Fiscal Year (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Amount (A) or (D) Price Common Stock 01/20/2005   G 1,210,567 (1) D $ 22.55 9,301,904 (4) D   Common Stock 09/21/2005   G 1,109,000 (1) D $ 32.34 9,301,904 (4) D   Common Stock 11/17/2005   G 575,000 (2) D $ 36.84 9,301,904 (4) D   Common Stock 11/17/2005   G 63,852 (3) D $ 36.84 9,301,904 (4) D Â

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

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SEC 2270 (9-02)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction 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 (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned at End of Issuer's Fiscal Year (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
RYAN SHIRLEY W C/O AON CORPORATE LAW DEPARTMENT 8TH FLOOR, 200 EAST RANDOLPH DRIVE CHICAGO, IL 60601	Â	Â	Â	Spouse of Director and Officer

Signatures

/s/ Shirley W. Ryan		02/09/2006
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	Shares transferred as a gift by the reporting person's living trust to the living trust of the reporting person's spouse, Patrick G. Ryan, Executive Chairman of the issuer. The shares reported as disposed of and the shares reported as beneficially owned by the reporting person are also reported by Mr. Ryan as disposed of indirectly, acquired directly and beneficially owned directly by him.
(2)	Shares disposed of as a gift by the reporting person's living trust to a charitable foundation controlled by the reporting person and Mr. Ryan. The shares reported as disposed of and the shares reported as beneficially owned by the reporting person are also reported by Mr. Ryan as disposed of indirectly and beneficially owned indirectly by him.
(3)	Shares disposed of as gifts to public charities by the reporting person's living trust.
(4)	The reporting person is also the indirect beneficial owner of 583,942 shares of common stock as trustee for her sons.

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