Aon plc — Director's Dealing 2010

Feb 23, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AON CORP (AOC)
CIK: 0000315293
Period of Report: 2010-02-20

Reporting Person: Case Gregory C (Director, Pres & CEO)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-02-20	Common Stock	M	3004	—	Acquired	134960	Direct
2010-02-20	Common Stock	F	885	$40.57	Disposed	134075	Direct
2010-02-21	Common Stock	M	12864	—	Acquired	146939	Direct
2010-02-21	Common Stock	F	3789	$40.57	Disposed	143150	Direct
2010-02-22	Common Stock	M	10273	—	Acquired	153423	Direct
2010-02-22	Common Stock	F	3173	$40.46	Disposed	150250	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2010-02-20	Restricted Stock Unit Award (Right to Receive)	$	M	3004	Disposed	2010-02-20	Common Stock (3004)	Direct
2010-02-21	Restricted Stock Unit Award (Right to Receive)	$	M	12864	Disposed	2010-02-21	Common Stock (12864)	Direct
2010-02-22	Restricted Stock Unit Award (Right to Receive)	$	M	10273	Disposed	2010-02-22	Common Stock (10273)	Direct

Footnotes

F1: Shares of common stock acquired upon the vesting of a restricted stock unit award.

F2: 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.

F3: The restricted stock unit award converts to shares of common stock on a 1-for-1 basis.