X0304 4 2012-02-16 0 0000315293 AON CORP AON 0001407939 Besio Gregory J C/O AON CORPORATE LAW DEPT 200 EAST RANDOLPH STREET, 8TH FL CHICAGO IL 60601 0 1 0 0 EVP/Chief HR Officer Common Stock 2012-02-16 4 A 0 50964 47.56 A 102621.682 D Common Stock 2012-02-16 4 F 0 19049 47.56 D 83572.682 D Common Stock 2012-02-17 4 M 0 1854 A 85426.682 D Common Stock 2012-02-17 4 F 0 769 47.62 D 84675.682 D Common Stock 2012-02-20 4 M 0 1016 A 85673.682 D Common Stock 2012-02-20 4 F 0 422 47.62 D 85251.682 D Common Stock 7197 I Through Aon Savings Plan and Supplemental Savings Plan Restricted Stock Unit Award (Right to Receive) 2012-02-16 4 A 0 4783 0 A 2013-02-16 2015-02-16 Common Stock 4783 4783 D Restricted Stock Unit Award (Right to Receive) 2012-02-17 4 M 0 1854 0 D 2012-02-17 2012-02-17 Common Stock 1854 3707 D Restricted Stock Unit Award (Right to Receive) 2012-02-20 4 M 0 1016 0 D 2012-02-20 2012-02-20 Common Stock 1016 0 D Represents shares of common stock issued upon the settlement of performance share units originally granted approximately three years ago under the fourth cycle of the Leadership Performance Program ("LPP4") on March 19, 2009. The number of shares issued was determined by the Organization and Compensation Committee of Aon's Board of Directors on February 16, 2012 based upon Aon's performance relative to a cumulative adjusted three year earnings per share target for the period beginning January 1, 2009 and ending December 31, 2011. In accordance with the terms of LPP4, and the achievement of specified growth targets under LPP4, settlement occurred at 124% of the original target value. The terms of LPP4 are more fully described in a Current Report on Form 8-K filed with the SEC on March 25, 2009, and in the plan document filed as Exhibit 10.5 to Aon's Quarterly Report on Form 10-Q for the quarter ended March 31, 2009 filed with the SEC on May 8, 2009. Shares of common stock withheld by the issuer for the payment of withholding taxes in connection with the settlement of a performance share unit award. Shares of common stock acquired upon the vesting of a restricted stock unit award. Shares of common stock withheld by the issuer for the payment of withholding taxes in connection with the vesting of a restricted stock unit award. The restricted stock unit award converts to shares of common stock on a 1-for-1 basis. The restricted stock unit award will vest in accordance with the terms of the Aon Stock Incentive Plan as follows: 33 1/3% of the awards will vest on each of the first through third anniversaries of the date of grant. Includes 81.698 shares acquired pursuant to the Aon employee stock purchase plan and shares acquired pursuant to dividend reinvestment. Exhibit List: Exhibit 24 - Power of Attorney of Gregory J. Besio. /s/ Matthew M. Rice - by Matthew M. Rice pursuant to a power of attorney from Gregory J. Besio 2012-02-21