Aon plc — Director's Dealing 2010

Oct 5, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AON CORP (AOC)
CIK: 0000315293
Period of Report: 2010-10-01

Reporting Person: FRADIN RUSSELL P (CEO/Chair - Aon Hewitt)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-10-01	Common Stock	A	27114	—	Acquired	27114	Direct
2010-10-01	Common Stock	A	35453	—	Acquired	62567	Direct
2010-10-01	Common Stock	A	50663	—	Acquired	113230	Direct
2010-10-01	Common Stock	A	127291	—	Acquired	240521	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2010-10-01	Restricted Stock Unit Award (Right to Receive)	$	A	50917	Acquired	2015-10-01	Common Stock (50917)	Direct
2010-10-01	Employee Stock Option (Right to Buy)	$29.15	A	149613	Acquired	2017-12-03	Common Stock (149613)	Direct
2010-10-01	Employee Stock Option (Right to Buy)	$20.44	A	271320	Acquired	2018-12-01	Common Stock (271320)	Direct
2010-10-01	Employee Stock Option (Right to Buy)	$17.65	A	193800	Acquired	2015-02-15	Common Stock (193800)	Direct
2010-10-01	Employee Stock Option (Right to Buy)	$31.99	A	147006	Acquired	2019-12-01	Common Stock (147006)	Direct
2010-10-01	Employee Stock Option (Right to Buy)	$17.65	A	234627	Acquired	2016-09-05	Common Stock (234627)	Direct

Footnotes

F1: Received pursuant to the Agreement and Plan of Merger, dated as of July 11, 2010, among Aon Corporation ("Aon"), Alps Merger Corp., Alps Merger LLC and Hewitt Associates, Inc. (the "Merger Agreement") in exchange for 42,620 shares of Hewitt common stock held directly. On the effective date of the merger, the closing price of Aon's common stock was $39.28.

F2: Received pursuant to the Merger Agreement in exchange for 55,727 shares of Hewitt common stock resulting from the settlement of Hewitt restricted stock units. On the effective date of the merger, the closing price of Aon's common stock was $39.28.

F3: Received pursuant to the Merger Agreement in exchange for 79,634 shares of Hewitt common stock resulting from the settlement of Hewitt performance share units. On the effective date of the merger, the closing price of Aon's common stock was $39.28.

F4: Current estimate based on anticipated tax withholding.

F5: Represents a fully vested restricted stock unit award that will be distributed upon the reporting person's departure from Aon. Received pursuant to the Employment Agreement dated as of September 30, 2010 between Aon Corporation and Russell P. Fradin.

F6: The restricted stock unit award will convert to shares of Aon common stock on a 1-for-1 basis.

F7: Restricted stock units will vest in accordance with the Aon Stock Incentive Plan as follows: 25% of the shares will vest on each of the second through fifth anniversaries of the date of grant.

F8: Represents an option to purchase shares of Hewitt common stock that was converted to an option to purchase shares of Aon common stock pursuant to the Merger Agreement. The option is fully vested and immediately exercisable.

F9: Represents a stock option granted pursuant to the Aon Stock Incentive Plan.