Aon plc — Director's Dealing 2012

Feb 21, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AON CORP (AON)
CIK: 0000315293
Period of Report: 2012-02-16

Reporting Person: O'Connor Michael J (ARS - COO)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-02-16	Common Stock	A	12741	—	Acquired	50650	Direct
2012-02-16	Common Stock	F	4018	$47.56	Disposed	46632	Direct
2012-02-17	Common Stock	M	2248	—	Acquired	48880	Direct
2012-02-17	Common Stock	F	707	$47.62	Disposed	48173	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-02-16	Restricted Stock Unit Award (Right to Receive)	$	A	5887	Acquired	2015-02-16	Common Stock (5887)	Direct
2012-02-17	Restricted Stock Unit Award (Right to Receive)	$	M	2248	Disposed	2012-02-17	Common Stock (2248)	Direct

Footnotes

F1: 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.

F2: 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.

F3: Shares of common stock acquired upon the vesting of a restricted stock unit award.

F4: 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.

F5: The restricted stock unit award converts to shares of common stock on a 1-for-1 basis.

F6: 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.