SC 13D/A

	UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
	Washington, D.C. 20549
	SCHEDULE 13D/A (Rule 13d-101)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO
13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO 13d-2(a)

Under the Securities Exchange Act of 1934
(Amendment No. 9)*

Aon Corporation

(Name of Issuer)

Common Stock, $1.00 Par Value

(Title of Class of Securities)

200166106

(CUSIP Number)

Lisa J. Reátegui
Sidley Austin Brown & Wood
Bank One Plaza
10 South Dearborn Street
Chicago, Illinois 60603

(Name, Address and Telephone Number of Person
Authorized to Receive Notices and Communications)

August 25, 2005

(Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. o

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

^* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No.   200166106
	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Patrick G. Ryan
	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)			o
		(b)			o
	3.	SEC Use Only
	4.	Source of Funds (See Instructions) OO
	5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)  o
	6.	Citizenship or Place of Organization U.S.A.
Number of Shares Beneficially Owned by Each Reporting Person With			7.	Sole Voting Power 14,588,734
			8.	Shared Voting Power  11,049,756
			9.	Sole Dispositive Power  14,184,734
			10.	Shared Dispositive Power  11,453,756
	11.	Aggregate Amount Beneficially Owned by Each Reporting Person  26,222,432
	12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)   o
	13.	Percent of Class Represented by Amount in Row (11)  8.23%
	14.	Type of Reporting Person (See Instructions) IN

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CUSIP No.   200166106
	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Shirley W. Ryan
	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)			o
		(b)			o
	3.	SEC Use Only
	4.	Source of Funds (See Instructions) OO
	5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)  o
	6.	Citizenship or Place of Organization U.S.A.
Number of Shares Beneficially Owned by Each Reporting Person With			7.	Sole Voting Power 583,942
			8.	Shared Voting Power  11,049,756
			9.	Sole Dispositive Power  583,942
			10.	Shared Dispositive Power  11,453,756
	11.	Aggregate Amount Beneficially Owned by Each Reporting Person  26,222,432
	12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)   o
	13.	Percent of Class Represented by Amount in Row (11)  8.23%
	14.	Type of Reporting Person (See Instructions) IN

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Introduction

This filing is being made jointly by Patrick G. Ryan and Shirley W. Ryan and relates to the common stock, $1.00 par value (“Aon Common Stock”), of Aon Corporation, a Delaware corporation (“Aon”).  These individuals own Aon Common Stock directly and Shirley W. Ryan acts as trustee of a trust to benefit members of the Ryan family. This filing amends the Schedule 13D previously filed by Patrick G. Ryan and Shirley W. Ryan.  Shirley W. Ryan is the spouse of Patrick G. Ryan.

On August 25, 2005, the Patrick G. Ryan Living Trust dated July 10, 2001 (the “PGR Living Trust”) entered into a written plan (the "Sales Plan") pursuant to Rule 10b5-1 under the Securities Exchange Act of 1934, as amended, under which the PGR Living Trust has instructed Goldman, Sachs & Co, as its agent, to sell up to 5,000,000 shares of Aon Common Stock from September 9, 2005 through June 15, 2006 subject to the terms, conditions and restrictions set forth in the Sales Plan.  The Sales Plan will terminate on the earliest of (i) August 25, 2006, (ii) the date on which all shares of Aon Common Stock subject to the Sales Plan have been sold, (iii) the date the Sales Plan is terminated by the PGR Living Trust in accordance with the terms of the Sales Plan and (iv) upon written notification of the death of Patrick G. Ryan.

Patrick G. Ryan and Shirley W. Ryan are filing this Amendment No. 9 to this Schedule 13D to report the changes in their beneficial ownership of Aon Common Stock.

Item 1.	Security and Issuer
This statement relates to the Aon Common Stock.  Aon is a Delaware corporation, the principal executive offices of which are located at 200 E. Randolph Drive, Chicago, Illinois  60601.
Item 2.	Identity and Background
The name, business address and present principal occupation or employment of each of the persons filing this statement are as follows:
Patrick G. Ryan:  Mr. Ryan is a director and Executive Chairman of Aon, a holding company that comprises a family of insurance brokerage, consulting and insurance underwriting subsidiaries.  Aon’s principal executive offices are as set forth in Item 1, and Mr. Ryan’s business address is c/o Aon at such address.
Shirley W. Ryan:  Mrs. Ryan is co-founder and president of Pathways Awareness Foundation, a foundation that promotes early detection and inclusion for infants and children with physical differences or disabilities, and President of Pathways Center for Children, an outpatient pediatric therapy clinic.  The business address of the foundation and the center, and Mrs. Ryan’s business address, are c/o Ryan Enterprises Group, Suite 2100, 150 North Michigan Ave., Chicago, Illinois  60601.
Neither of the persons filing this statement has, during the last five years, been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).

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Neither of the persons filing this statement has, during the last five years, been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding been or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, Federal or State securities laws or finding any violation with respect to such laws.
Each of the persons filing this statement is a citizen of the United States of America.
Item 3.	Source and Amount of Funds or Other Consideration
No funds or other consideration were borrowed or otherwise obtained for the purpose of effecting the transactions described herein.
Item 4.	Purpose of Transaction
Patrick G. Ryan, as trustee of the PGR Living Trust, put in place the Sales Plan to sell a portion of the Aon Common Stock held by him in order to address certain personal estate, charitable and other financial matters. The sales of Aon Common Stock by the PGR Living Trust pursuant to the Sales Plan will decrease the aggregate beneficial ownership of Patrick G. Ryan and Shirley W. Ryan.  The transfers will result in an aggregate decrease in the number of shares as to which Patrick G. Ryan has sole or shared power to vote or dispose, and a decrease in the number of shares as to which Shirley W. Ryan has shared power to vote or dispose.
Patrick G. Ryan is Executive Chairman and a director of Aon and in such capacity participates in the decisions made by the Board of Directors of Aon in the ordinary course of the business of Aon.  Except as may arise in connection with the normal execution of the positions that Patrick G. Ryan holds with Aon, or as provided in the next paragraph, none of the persons filing this statement has any present plans or proposals which relate to or would result in (a) the acquisition by any person of additional securities of Aon or the disposition of securities of Aon; (b) an extraordinary corporate transaction, such as a merger, reorganization or liquidation, involving Aon or any of its subsidiaries; (c) a sale or transfer of a material amount of assets of Aon or of any of its subsidiaries; (d) any change in the present board of directors or management of Aon, including any plans or proposals to change the number or term of directors or to fill any existing vacancies on the board; (e) any material change in the present capitalization or dividend policy of Aon; (f) any other material change in Aon’s business or corporate structure; (g) changes in Aon’s charter, bylaws or instruments corresponding thereto or other actions which may impede the acquisition of control of Aon by any person; (h) causing a class of securities of Aon to be delisted from a national securities exchange or to cease to be authorized to be quoted in an inter-dealer quotation system of a registered national securities association; (i) a class of equity securities of Aon becoming eligible for termination of registration pursuant to Section 12(g)(4) of the Securities Exchange Act of 1934; or (j) any action similar to any of those enumerated above.
Any of the reporting persons may from time to time acquire additional securities of Aon or dispose of shares of Aon Common Stock.  Such acquisitions or dispositions may be made in the open market or in privately negotiated transactions.  In addition, Patrick G. Ryan may acquire additional shares of Aon Common Stock upon exercise of employee stock options

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granted to him from time to time by Aon or under employee benefit plans of Aon in which he participates.
Item 5.	Interest in Securities of the Issuer
The persons filing this statement beneficially own in the aggregate (without duplication) 26,222,432 shares of Aon Common Stock, representing approximately 8.23% of the 318,521,576 issued and outstanding shares of Aon Common Stock as of June 30, 2005.
The shares of Aon Common Stock beneficially owned by such persons are beneficially owned as follows:

	Sole Power to Vote or Direct the Vote		Shared Power to Vote or Direct the Vote		Sole Power to Dispose or Direct the Disposition		Shared Power to Dispose or Direct the Disposition
Patrick G. Ryan	14,588,734	(1)	11,049,756	(2)	14,184,734	(1)	11,453,756	(3)
Shirley W. Ryan	583,942		11,049,756	(4)	583,942		11,453,756	(5)

(1)Includes 1,907,500 shares which Patrick G. Ryan has the right to acquire within 60 days of August 25, 2005 upon exercise of employee stock options granted to him by Aon.  Also includes 388,740 shares of Aon Common Stock beneficially owned under the ESOP Account of the Aon Savings Plan and allocated to Mr. Ryan and beneficially owned and attributed to Mr. Ryan pursuant to his investment in the Aon Common Stock Fund of the Aon Savings Plan.

(2)           Shares power to vote with Shirley W. Ryan.

(3)           Shares power to dispose with Shirley W. Ryan.

(4)           Shares power to vote with Patrick G. Ryan.

(5)           Shares power to dispose with Patrick G. Ryan.

No transactions, other than as described above, in Aon Common Stock were effected by any of the persons filing this statement within the past sixty days.
Item 6.	Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer
The following agreements have been entered into previously by the persons filing this statement with respect to the securities of Aon and remain in effect: 1.  Stock Restriction Agreement dated July 16, 2001 among Aon, Patrick G. Ryan, Shirley W. Ryan, Patrick G. Ryan, Jr., Robert J.W. Ryan and certain trusts for which one or more of such persons is trustee.

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2.  Escrow Agreement dated July 16, 2001 among Aon, Patrick G. Ryan, Shirley W. Ryan, Patrick G. Ryan, Jr., Robert J.W. Ryan, certain trusts for which one or more of such persons is trustee and American National Bank and Trust Company of Chicago, as escrow agent. Patrick G. Ryan and certain trusts for whom he or Shirley W. Ryan is a trustee have revolving and other credit facilities with various financial institutions.  Certain of the shares of Aon Common Stock beneficially owned by the persons filing this statement (but not including the shares held pursuant to the Escrow Agreement) have been pledged (subject to a right to withdraw such shares from the pledge depending on loan-to-collateral ratios) to secure repayment of such amounts as may be outstanding under such facilities from time to time.  Additional shares of Aon Common Stock may be pledged by such persons from time to time hereafter to secure borrowings under such facilities or other facilities entered into in the future.
Item 7.	Material to Be Filed as Exhibits
Exhibit I                          Agreement of Joint Filing, dated September 13, 2005

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SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, correct and complete.

/s/ Patrick G. Ryan

Patrick G. Ryan

Dated: September 13, 2005

/s/ Shirley W. Ryan

Shirley W. Ryan

Dated: September 13, 2005

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EXHIBIT INDEX

Exhibit I                          Agreement of Joint Filing, dated September 13, 2005

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EX-1

EXHIBIT I

AGREEMENT OF JOINT FILING

Pursuant to Rule 13d-1(k)(1)(iii) of Regulation 13D-G of the General Rules and Regulations of the Securities and Exchange Commission under the Securities Exchange Act of 1934, as amended, the undersigned agree that the statement to which this exhibit is attached is filed on behalf of each of them in the capacities set forth below.

Date:  September 13, 2005

/s/ Patrick G. Ryan

Patrick G. Ryan

/s/ Shirley W. Ryan

Shirley W. Ryan