SEC Form 3
FORM 3 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number: 3235-0104
Estimated average burden
hours per response: 0.5
1. Name and Address of Reporting Person*
Hayley Kathryn

(Last) (First) (Middle)
AON CORPORATION - CORPORATE LAW DEPT
200 EAST RANDOLPH STREET, 8TH FLOOR

(Street)
CHICAGO IL 60601

(City) (State) (Zip)
2. Date of Event Requiring Statement (Month/Day/Year)
04/01/2008
3. Issuer Name and Ticker or Trading Symbol
AON CORP [ AOC ]
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director 10% Owner
X Officer (give title below) Other (specify below)
ACW - Chief Executive Officer
5. If Amendment, Date of Original Filed (Month/Day/Year)
6. Individual or Joint/Group Filing (Check Applicable Line)
X Form filed by One Reporting Person
Form filed by More than One Reporting Person
Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock 819 D
Table II - Derivative Securities Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4) 2. Date Exercisable and Expiration Date (Month/Day/Year) 3. Title and Amount of Securities Underlying Derivative Security (Instr. 4) 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 6. Nature of Indirect Beneficial Ownership (Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Restricted Stock Unit Award (Right to Receive) (1) 06/14/2011 Common Stock 80,000 (2) D
Restricted Stock Unit Award (Right to Receive) (3) 03/15/2010 Common Stock 4,088 (2) D
Employee Stock Option (Right to Buy) (4) 06/14/2016 Common Stock 100,000 33.345 D
Explanation of Responses:
1. Awards granted pursuant to the Aon Stock Incentive Plan that will vest as follows: one-third of the awards will vest on each of the third through fifth anniversaries of the date of grant. The date of grant was June 14, 2006.
2. The restricted stock unit award converts to shares of common stock on a 1-for-1 basis.
3. Awards granted pursuant to the Aon Stock Incentive Plan that will vest as follows: 22.22% of the awards will vest on each of the first and second anniversaries of the date of grant, and 55.56% of the awards will vest on the third anniversary of the date of grant. The date of grant was March 15, 2007, and the amount of the initial grant was 5,257 restricted stock units, 1,169 of which have previously vested.
4. Options granted pursuant to the Aon Stock Incentive Plan that will vest as follows: one-third of the options will vest on each of the second through fourth anniversaries of the date of grant. The date of grant was June 14, 2006.
/s/ Jennifer L. Kraft - by Jennifer L. Kraft pursuant to a power of attorney from Kathryn Hayley 04/10/2008
** Signature of Reporting Person Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.