Aon plc — Director's Dealing 2012

Mar 19, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AON CORP (AON)
CIK: 0000315293
Period of Report: 2012-03-15

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

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-02-29	Common Stock	G	5000	—	Disposed	559198	Direct
2012-03-15	Common Stock	M	82364	$41.365	Acquired	641562	Direct
2012-03-15	Common Stock	S	82364	$48.95	Disposed	559198	Direct
2012-03-16	Common Stock	M	8203	$41.365	Acquired	567401	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-03-15	Employee Stock Option (Right to Buy)	$41.365	M	82364	Disposed	2012-03-17	Common Stock (82364)	Direct
2012-03-16	Employee Stock Option (Right to Buy)	$41.365	M	8203	Disposed	2012-03-17	Common Stock (8203)	Direct

Footnotes

F1: The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on February 8, 2012.

F2: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $48.775 to $49.09, inclusive. The reporting person undertakes to provide to Aon Corporation, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F3: Vesting occurred in accordance with the terms of the Aon Stock Incentive Plan as follows: 33.34% of the options vested on the first anniversary of the date of grant, and 33.33% of the options vested on each of the second and third anniversaries of the date of grant.

F4: Stock option granted pursuant to the Aon Stock Incentive Plan.