8-K

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SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the
Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 5, 2003

Aon CORPORATION
(Exact name of Registrant as Specified in Its Charter)

Delaware (State or Other Jurisdiction of Incorporation)	1-7933 (Commission File Number)	36-3051915 (IRS Employer Identification No.)
200 East Randolph Street, Chicago, Illinois (Address of Principal Executive Offices)		60601 (Zip Code)

Registrant's Telephone Number, Including Area Code: (312) 381-1000

Not Applicable
(Former Name or Former Address, if Changed Since Last Report)

Item 7.    Financial Statements, Pro Forma Financial Information and Exhibits.

(a)—(b)	Not applicable.
(c)	Exhibits:

Exhibit Number	Description of Exhibit
99.1	Press Release issued by the Company on May 5, 2003.

Item 9.    Regulation FD Disclosure.

        The information required by Item 12. Results of Operations and Financial Condition is being provided under Item 9 pursuant to SEC guidance set forth in SEC Release No. 33-8216.

        The information included in this section is intended to be furnished pursuant to Item 12. Results of Operations and Financial Condition. Such information, including the exhibit hereto, shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, nor shall it be deemed incorporated by reference into any filing made under the Securities Act of 1933, except as expressly set forth by specific reference in such filing.

        On May 5, 2003, Aon Corporation (the "Company") issued a press release (the "Press Release") announcing its results of operations for the quarter ended March 31, 2003. A copy of the Press Release is attached hereto as Exhibit 99.1.

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SIGNATURES

        Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

	Aon CORPORATION
	By:	/s/  PATRICK G. RYAN Patrick G. Ryan Chairman and Chief Executive Officer
Date: May 5, 2003

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EXHIBIT INDEX

        The following is a list of the exhibits filed herewith.

Exhibit Number	Description of Exhibit
99.1	Press Release issued by the Company on May 5, 2003.

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Item 7. Financial Statements, Pro Forma Financial Information and Exhibits.
Item 9. Regulation FD Disclosure.

SIGNATURES
EXHIBIT INDEX

EX-99.1

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Exhibit 99.1

Aon Reports First Quarter 2003 Results;
Operating Segment Pretax Income Grows 10%

CHICAGO, IL—May 5, 2003—Aon Corporation (NYSE: AOC) today reported first quarter 2003 earnings. Aon is providing enhanced segment disclosure that includes more detailed sub-segment revenue information and an updated presentation of segment reporting, as previously disclosed. First quarter 2003 segment results also reflect a refined methodology for allocating certain centrally controlled costs.

        Supplemental financial information covering 2001 and 2002 was provided in a Form 8-K on May 2, 2003 to conform the prior period segment presentation to the new format and to facilitate comparisons between periods. The Company's historical consolidated earnings per share, net income and pretax earnings have not changed as a result of the segment reclassifications and enhanced presentation.

First Quarter Review

        Consolidated revenues of $2.388 billion increased 14% from a year ago. Foreign exchange translations accounted for 5% of the increase. First quarter 2003 net income was $152 million compared with $160 million a year ago. Earnings per share were $0.48 and $0.57, respectively. A 14% increase in average dilutive common and common equivalent shares outstanding resulting from the fourth quarter 2002 capital enhancement actions impacted the earnings per share comparisons.

        First quarter 2003 results included a negative $37 million pretax World Trade Center (WTC) item ($0.07 per share), approximately $32 million pretax ($0.06 per share) of increased pension costs and a $34 million pretax ($0.07 per share) increase in equity and other investment income within the Corporate and Other segment. The investment income improvement was due largely to a $45 million pretax increase in the value of Endurance Specialty Holdings, Ltd. warrants (received as part of Aon's co-sponsorship investment in Endurance), offset somewhat by impairment write-downs of $28 million pretax in the quarter.

        First quarter 2002 results included a favorable pretax $48 million ($0.11 per share) tax item that was partially offset by a previous spin off plan related special charge of $5 million pretax ($0.01 per share).

        Patrick G. Ryan, chairman and CEO of Aon Corporation, said, "We achieved double-digit organic revenue growth in our operating segments driven by continued client demand for our products and services. Although pension costs increased in the quarter compared to last year, improvements in our risk and insurance brokerage businesses more than offset these incremental costs, and brokerage margins improved." Ryan added, "Consulting revenue growth was good but margins were impacted, in part, by an increase in lower margin outsourcing business. Insurance underwriting also had good top line growth, but underperformance in certain warranty and P&C lines compressed margins."

First Quarter Segment Review

For first quarter 2003, the revised cost allocation methodology noted above reduced Consulting and Insurance Underwriting segment pretax income by approximately $4 million and $3 million, respectively, with the $7 million offset reflected in the Risk and Insurance Brokerage Services segment. The revised methodology improves the assignment of costs, which are controlled on a centralized basis, to the operating segments.

Risk and Insurance Brokerage Services first quarter revenue grew 19% to $1.374 billion. Organic revenue growth was 12% for the segment, up from 10% in fourth quarter 2002. On a comparable currency basis, revenue was up 12%.

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        Pretax income grew 22% to $230 million and pretax margins expanded to 16.7% from 16.3% a year ago. Reinsurance and international brokerage operations had strong results and Americas brokerage improved through new business development and better retention rates. Managing underwriting profits, which are included in Americas brokerage, increased compared to unusually low levels a year ago, but claims services performance was down for the quarter. Pension costs increased approximately $27 million in the segment.

Consulting segment revenue rose 21% to $282 million in the quarter, or 15% excluding the impact of foreign exchange rates. Organic revenue growth was 13%, driven mostly by new outsourcing business initiated in third quarter 2002 and good growth in the United Kingdom and Continent of Europe. Organic revenue growth excluding outsourcing business was 6%.

        Pretax income was $20 million compared with $27 million one year ago. The pretax margin was 7.1% compared with 11.6% in first quarter 2002. Increased centrally allocated costs, an increasing mix of lower margin outsourcing revenues and increased pension costs were the principal factors compressing margins.

Insurance Underwriting segment revenue increased 9% to $709 million in first quarter 2003, driven by warranty and select property and casualty insurance premium growth, primarily related to certain limited lines managed by Aon's managing underwriting group. Investment income decreased $14 million. Excluding the impact of foreign exchange rates, revenues rose 7%. In late 2002, Aon decided that by the end of 2003 it would discontinue certain unprofitable accident and health insurance underwriting operations in Mexico, Argentina and Brazil, and exit its large company group life business. There were $7 million of revenues and $2 million of losses and other costs attributable to these businesses in the quarter compared to $18 million in revenues and approximately breakeven results in first quarter 2002.

        Pretax income was $63 million compared with $68 million in first quarter 2002, which included $5 million ($0.01 per share) previously reported as a special charge.

        Pretax margins were 8.9% in first quarter 2003 and 11.2% in first quarter 2002 (adjusted for the $5 million special charge noted above). Underperformance in certain warranty and property and casualty lines negatively impacted the margin, due partly to higher loss costs and expenses, some of which are related to lines in runoff.

Corporate and Other segment revenue of $35 million declined from $49 million in first quarter 2002, which included a favorable pretax $48 million tax settlement. In first quarter 2003, gross investment writedowns were $28 million compared with $8 million in the prior year quarter.

        Investment income included a $45 million increase in the value of warrants acquired through Aon's co-sponsorship investment in Endurance in December 2001. Endurance completed its initial public offering in first quarter 2003. As of March 31, 2003, Aon owned approximately 4 million warrants.

        The Corporate and Other segment pretax loss was $57 million compared with a pretax loss of $13 million in the prior year quarter. The increased loss is due primarily to reduced revenue and a negative $37 million pretax WTC item described below.

        In order to resume business operations and minimize the loss caused by the WTC disaster, Aon secured temporary office space in Manhattan. Subsequently, permanent space was leased, and during the first quarter Aon assigned all of the temporary space to another company. The costs relating to this assignment transaction were $37 million pretax ($0.07 per share). We will incur additional costs related to this assignment in future quarters, which in aggregate will not exceed $15 million. Aon will include all of these costs as part of its final, overall WTC property insurance claim; however, accounting principles do not allow Aon to offset this expense in the current quarter with an insurance recoverable. The normal claims process continues under the Company's property insurance coverage.

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Other Item

        After netting the effect of currency hedges, the positive impact of foreign currency translations was approximately $0.03 per share. The comparable impact on first quarter 2002 results was immaterial.

Financial Strength Highlights

        Total debt was reduced to approximately $1.7 billion at March 31, 2003, down from $1.8 billion at December 31, 2002. Commercial paper and preferred securities outstanding were unchanged for the same periods at $1 million and $752 million, respectively. Stockholders' equity was approximately $4.1 billion at March 31, 2003, up from $3.9 billion at year-end 2002. At March 31, 2003, Aon's total debt and preferred securities as a percentage of total capital improved to 37% versus 40% at December 31, 2002.

        Short-term and fixed maturity investments at March 31, 2003 comprised approximately 90% of Aon's investment portfolio. More than 93% of the fixed income securities portfolio is investment grade.

        Aon's senior debt is rated "A-" by Standard and Poor's and Fitch, and Baa2 by Moody's. Aon's principal insurance underwriting subsidiaries are rated "A" by A.M. Best for their claims paying ability.

Future Outlook

        Mr. Ryan commented, "Our fundamental businesses are strong and we continue to be comfortable with a 2003 earnings per share range of $1.90 to $2.00, excluding the WTC item, based on our current outlook."

        The future outlook may be impacted by internal and external factors, including economic conditions, equity markets and premium rate developments.

        The Company will host an audio webcast today at 10:00 a.m. (CDT) that can be accessed at www.aon.com.

        Aon Corporation (www.aon.com) is a holding company that is comprised of a family of insurance brokerage, consulting and insurance underwriting subsidiaries.

This press release contains certain statements relating to future results, which are forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995. These forward-looking statements are subject to certain risks and uncertainties that could cause actual results to differ materially from either historical or anticipated results, depending on a variety of factors. Potential factors that could impact results include the general economic conditions in different countries around the world, fluctuations in global equity and fixed income markets, exchange rates, rating agency actions, pension funding, changes in commercial property and casualty markets and commercial premium rates, the competitive environment, the actual costs of resolution of contingent liabilities and other loss contingencies, the heightened level of potential errors and omissions liability arising from placements of complex policies and sophisticated reinsurance arrangements in an insurance market in which insurer reserves are under pressure, and the timing and resolution of related insurance and reinsurance issues relating to the events of September 11, 2001. Further information concerning the Company and its business, including factors that potentially could materially affect the Company's financial results, are contained in the Company's filings with the Securities and Exchange Commission.

###

Investor Contact:	Sean O'Neill Vice President, Financial Relations 312-381-3983
	or
Media Contact:	Al Orendorff Director, Public Relations 312-381-3153

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Aon Corporation
Consolidated Summary of Operations

			First Quarter Ended
			Mar. 31, 2003			Mar. 31, 2002			Percent Change
			(millions except per share data)
Revenue
	Brokerage commissions and fees		$	1,676		$	1,444		16	%
	Premiums and other			632			535		18
	Investment income			80			109		(27	)
		Total revenue		2,388			2,088		14
Expenses
	General expenses			1,709			1,463		17
	Benefits to policyholders			345			314		10
	Interest expense			28			29		(3	)
	Amortization of intangible assets			13			11		18
	Unusual charges—World Trade Center			37			—		N/A
		Total expenses		2,132			1,817		17
Income Before Income Tax and Minority Interest				256			271		(6	)
	Provision for income tax (37% in 2003 and 2002)			95			101		(6	)
Income Before Minority Interest				161			170		(5	)
	Minority interest—8.205% trust preferred capital securities			(9	)		(10	)	(10	)
Net Income			$	152		$	160		(5	)%
	Preferred stock dividends			(1	)		(1	)	—
Net Income Available for Common Stockholders			$	151		$	159		(5	)%
Net Income Per Share:
	Basic net income per share		$	0.48		$	0.58		(17	)%
	Dilutive net income per share		$	0.48		$	0.57		(16	)%
	Dilutive average common and common equivalent shares outstanding			315.2			276.6		14	%

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Aon Corporation
Segments

			First Quarter Ended
			Mar. 31, 2003			Mar. 31, 2002			Percent Change		Organic Revenue Growth(5)
			(millions)
Revenue
Risk and insurance brokerage services(1)
	Risk management and insurance brokerage—Americas		$	507		$	448		13	%	13	%
	Risk management and insurance brokerage—International			524			420		25		11
	Reinsurance brokerage and related services			242			199		22		15
	Claims services			101			90		12		7
		Total risk and insurance brokerage services		1,374			1,157		19		12
Consulting(2)
	Benefits, compensation, management and communications consulting			209			183		14		6
	Human resource outsourcing			73			50		46		38
		Total consulting		282			233		21		13
Insurance underwriting(3)
	Accident & health and life			399			389		3		5
	Warranty, credit and property & casualty			310			260		19		20
		Total insurance underwriting		709			649		9		12
Corporate and other				35			49		(29	)	N/A
Intersegment revenues(4)				(12	)		—		N/A		N/A
		Total revenue	$	2,388		$	2,088		14	%	12	%
Income (Loss) Before Income Tax and Minority Interest
	Risk and insurance brokerage services		$	230		$	189		22	%
	Consulting			20			27		(26	)
	Insurance underwriting			63			68		(7	)
	Corporate and other			(57	)		(13	)	N/A
		Total income before income tax and minority interest	$	256		$	271		(6	)%

(1)

Includes investment income of $20 million and $21 million for the first quarter ended March 31, 2003 and 2002, respectively.

(2)

Includes investment income of $1 million for both the first quarter ended March 31, 2003 and 2002.

(3)

Includes investment income of $28 million and $42 million, of which $2 million and $12 million pertain to interest earned on investments underlying investment-type contracts, for the first quarter ended March 31, 2003 and 2002, respectively.

(4)

The above numbers include intersegment revenues of $12 million for the first quarter ended March 31, 2003 which have been eliminated in the consolidated summary of operations. Intersegment revenues in periods prior to March 31, 2003 have not been eliminated in the consolidated summary of operations due to immateriality.

(5)

Organic revenue growth excludes the impact of acquisitions, dispositions, transfers, investment income, foreign exchange and unusual items. Written premiums and fees are the basis for organic revenue growth within the Insurance Underwriting segment.

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Aon Corporation
Corporate and Other

			First Quarter Ended
			Mar. 31, 2003			Mar. 31, 2002			Percent Change
			(million)
Revenue
Investment Income:
	Limited partnership investments		$	—		$	9		(100	)%
	Income from marketable equity securities and other investments			53			3		+500
	Interest on tax refund			—			48		(100	)
	Net loss on disposals and related expenses(1)			(22	)		(15	)	N/A
		Total investment income		31			45		(31	)
Auto finance service revenue				4			4		—
		Total revenue		35			49		(29	)
Expenses
	General expenses(2)			27			33		(18	)
	Interest expense			28			29		(3	)
	Unusual charges—World Trade Center			37			—		N/A
		Total expenses		92			62		48
Loss before income tax			$	(57	)	$	(13	)	N/A	%

(1)

Includes impairment writedowns of $28 million and $8 million for the first quarter ended March 31, 2003 and 2002, respectively.

(2)

Includes $11 million and $10 million of costs for the first quarter ended March 31, 2003 and 2002, respectively, related to the auto finance operations.

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Aon Reports First Quarter 2003 Results; Operating Segment Pretax Income Grows 10%
Aon Corporation Consolidated Summary of Operations
Aon Corporation Segments
Aon Corporation Corporate and Other