UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Aon Corporation (Name of Issuer) Common Stock (Title of Class of Securities) 037389103 (CUSIP Number) December 30, 2011 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is filed: [X] Rule 13d-1(b) [ ] Rule 13d-1(c) [ ] Rule 13d-1(d) *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 the disclosures provided in a prior cover page. The information required in 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: 037389103 Page 1 of 5 1 NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) The Growth Fund of America, Inc. 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) (b) 3 SEC USE ONLY 4 CITIZENSHIP OR PLACE OF ORGANIZATION Maryland 5 SOLE VOTING POWER 16,608,995 6 SHARED VOTING POWER NUMBER OF SHARES NONE BENEFICIALL Y OWNED BY 7 SOLE DISPOSITIVE POWER EACH REPORTING NONE PERSON WITH: 8 SHARED DISPOSITIVE POWER NONE 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 16,608,995 See Additional information in Item 4. Please note: Under certain circumstances independent directors from The Growth Fund of America, Inc.'s Board of Directors may vote the shares held by the fund. These share may also be reflected in a filing made by Capital Research Global Investors and/or Capital World Investors. 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 5.1% 12 TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) IV CUSIP: 037389103 Page 2 of 5 SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Schedule 13G Under the Securities Exchange Act of 1934 Amendment No. Item 1(a) Name of Issuer: Aon Corporation Item 1(b) Address of Issuer's Principal Executive Offices: Aon Center 200 East Randolph St. Chicago, IL 60601 Item 2(a) Name of Person(s) Filing: The Growth Fund of America, Inc. Item 2(b) Address of Principal Business Office or, if none, Residence: 333 South Hope Street Los Angeles, CA 90071 Item 2(c) Citizenship: N/A Item 2(d) Title of Class of Securities: Common Stock Item 2(e) CUSIP Number: 037389103 Item 3 If this statement is filed pursuant to sections 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a: (d) [X] Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8). Item 4 Ownership Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1. (a) Amount beneficially owned: (b) Percent of class: (c) Number of shares as to which the person has: (i) Sole power to vote or to direct the vote: (ii) Shared power to vote or to direct the vote: (iii) Sole power to dispose or to direct the disposition of: (iv) Shared power to dispose or to direct the disposition of: See page 2 CUSIP: 037389103 Page 3 of 5 The Growth Fund of America, Inc., an investment company registered under the Investment Company Act of 1940, which is advised by Capital Research and Management Company ("CRMC"), is the beneficial owner of 16,608,995 shares or 5.1% of the 323,289,389 shares believed to be outstanding. CRMC manages equity assets for various investment companies through two divisions, Capital Research Global Investors and Capital World Investors. These divisions generally function separately from each other with respect to investment research activities and they make investment decisions and proxy voting decisions for the investment companies on a separate basis. Item 5 Ownership of Five Percent or Less of a Class. If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following: [ ] Item 6 Ownership of More than Five Percent on Behalf of Another Person: N/A Item 7 Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person: N/A Item 8 Identification and Classification of Members of the Group: N/A Item 9 Notice of Dissolution of Group: N/A Item 10 Certification By signing below, I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect. Signature After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. Date: February 10, 2012 Signature: Patrick F. Quan*** Name/Title: Patrick F. Quan - Secretary The Growth Fund of America, Inc. CUSIP: 037389103 Page 4 of 5 ***By /s/ Walter R. Burkley Walter R. Burkley Attorney-in-fact Signed pursuant to a Power of Attorney dated December 21, 2007 included as an Exhibit to Schedule 13G filed with the Securities and Exchange Commission by The Growth Fund of America, Inc on February 11, 2008 with respect to Southwest Airlines Company. CUSIP: 037389103 Page 5 of 5