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): August 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 August 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 August 5, 2003, Aon Corporation (the "Company") issued a press release (the "Press Release") announcing its results of operations for the quarter and six months ended June 30, 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/  DAVID P. BOLGER David P. Bolger Executive Vice President and Chief Financial Officer
Date: August 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 August 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 Second Quarter and Six Months 2003 Results

CHICAGO, IL—August 5, 2003—Aon Corporation (NYSE: AOC) today reported second quarter and six months 2003 results.

Second Quarter and Six Months Highlights

Net income for the second quarter was $146 million or $0.46 per share compared with breakeven results in the year ago period. Six months results increased to $298 million or $0.94 per share from $160 million or $0.57 per share in 2002. Excluding an expected $9 million ($0.02 per share) unusual World Trade Center (WTC) charge initially noted in first quarter 2003, net income per share was $0.48 for the second quarter. Six months net income per share, excluding unusual WTC charges ($0.09 per share) was $1.03.

Consolidated revenues grew 15% for the second quarter and six months to $2.4 billion and $4.8 billion, respectively, versus the year ago periods. Continued demand for Aon's services and products and improved investment income drove the increases. Foreign exchange translations accounted for 5% of the growth for both the quarter and first half.

Patrick G. Ryan, chairman and CEO of Aon Corporation, said, "Second quarter results showed steady improvement in our risk management and insurance brokerage operations, much better results in insurance underwriting, and good core performance in consulting given the current economic climate. Client demand for our services and products continues to be robust, as evidenced by our solid organic revenue growth, and I am encouraged by the progress we have made in our businesses."

Ryan added, "We are working diligently to increase our operating margins by further tightening our expense management, and I believe we can increase our productivity as we continue to grow revenues."

Second Quarter Segment Review

Risk and Insurance Brokerage Services second quarter revenue grew 17% to $1.424 billion. Organic revenue growth for the total segment was 11%. Within the segment, organic revenue growth was 14% for the Americas (up from 13% in first quarter 2003), 10% for International, 13% for Reinsurance and 2% for Claims Services.

Pretax income increased 22% to $175 million from $144 million in second quarter 2002. Pretax margins improved to 12.3% from 11.9%. Excluding a previously reported $6 million special credit, pretax income in second quarter 2002 was $138 million and the pretax margin was 11.4%. As expected, defined benefit pension costs increased by approximately $28 million year-to-year in the segment. Claims services second quarter pretax income declined approximately $19 million from the prior year. Investment income was $8 million lower in the second quarter compared with a year ago, and second quarter 2002 results included $7 million of transition costs related to the business transformation.

Mr. Ryan commented, "Margins were up, despite increased pension costs and a decline in claims services results, which shows that most of our brokerage businesses have performed better than last year. Excluding the claims services decline, the second quarter brokerage margin was in line with our original expectation." Mr. Ryan added, "There is seasonality within the year, and our brokerage margins are highest in the fourth quarter. Given our current outlook, we continue to expect that the 2003 brokerage margin will exceed full year 2002."

Reinsurance operations, particularly in the U.S., had excellent results and U.S. retail brokerage and managing underwriting improved significantly from a year ago, driven by higher retention rates and new business development. International brokerage continued to have solid results. In claims services, actions have been and are being taken to improve the financial performance of this business.

Consulting revenue rose 19% to $294 million, or 9% on an organic basis. Human resource outsourcing was the principal growth area with 26% organic revenue growth. Non-outsourcing business grew 5% on an organic basis, mostly due to slower hiring and less discretionary spending by clients in response to challenging economic conditions.

Pretax income was $21 million compared with $23 million one year ago, and the pretax margin was 7.1% versus 9.3%. An increasing mix of lower margin outsourcing business factored into the comparisons; however, the profitability of these multi-year contracts is expected to improve in future periods.

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Insurance Underwriting revenue was $692 million compared with $750 million in second quarter 2002. The decline in reported revenues was primarily the result of the "back-to-basics" strategy within A&H underwriting that was announced in fourth quarter 2002. Additionally, investment income decreased $11 million, primarily from the runoff of guaranteed investment contracts.

Organic revenue growth, based on written premiums, was 8%, driven by credit and select property and casualty premiums.

Pretax income was $64 million compared with $2 million in second quarter 2002. Pretax margins grew to 9.2% from 0.3%. Excluding a previously reported $3 million special charge in second quarter 2002, pretax income was $5 million and the pretax margin was 0.7%. The "back-to-basics" focus in accident and health (A&H) underwriting significantly improved the benefits payout ratio, which contributed to the margin increase.

Second quarter 2002 results included a $15 million pretax non-claim litigation reserve and a $36 million pretax expense related to the termination of NPS, an independent managing general agent.

Corporate and Other segment revenue of $44 million improved from a negative $91 million in second quarter 2002, due mostly to lower impairment write downs and increased income from equity securities. Investment income in second quarter 2003 included $21 million from an increase in the value of Endurance Specialty Holdings Limited (NYSE: ENH) warrants. Aon co-sponsored the formation of Endurance in 2001 and made an initial investment of $227 million.

The Corporate and Other segment pretax loss was $15 million compared to a pretax loss of $153 million a year ago, principally due to improved revenues. A $9 million unusual WTC charge was incurred in the quarter. This previously anticipated charge, originally noted in Aon's first quarter 2003 earnings release, relates to temporary office space secured in Manhattan following the WTC disaster. Aon has included these costs as part of its WTC property insurance claim, which continues to be processed.

Second Quarter and Six Months Earnings Per Share: Review of Selected Items

The table below outlines certain items that influenced the second quarter and six months results.

		Second Quarter						Six Months
Earnings Per Share (EPS) Analysis: credit (charge)
		2003			2002			2003			2002
Reported Dilutive EPS		$	0.46		$	0.00		$	0.94		$	0.57
	Unusual charges—WTC		(0.02	)		—			(0.09	)		—
	Special charges—spin off expenses		—			(0.01	)		—			(0.02	)
	Special credits—business transformation plan		—			0.01			—			0.01
	One-time tax related item		—			—			—			0.11
	Cumulative adjustment—other than temporary impairments		—			(0.13	)		—			(0.12	)
	NPS related costs		—			(0.08	)		—			(0.08	)
	Underwriting segment non-claim litigation reserves		—			(0.03	)		—			(0.03	)
	Losses and other costs for certain insurance underwriting units being discontinued		(0.01	)		(0.01	)		(0.01	)		(0.01	)
	Additional spin-off plan and related expenses not reflected as special charges		—			(0.01	)		—			(0.02	)

In addition to the items shown above, defined benefit pension costs increased by approximately $34 million pretax ($0.07 per share) in second quarter 2003 compared to a year ago. After netting the effect of currency hedges, the positive impact of foreign currency translations was approximately $0.03 per share in the quarter.

Financial Strength Highlights

Total debt decreased to approximately $1.76 billion at June 30, 2003 from $1.79 billion at December 31, 2002. Preferred securities outstanding were $752 million for both periods. Stockholders' equity was approximately $4.3 billion at June 30, 2003, up from $3.9 billion at year-end 2002. At June 30, 2003, Aon's total debt and preferred securities as a percentage of total capital improved to 37% from 40% at December 31, 2002.

Approximately 90% of Aon's investment portfolio at quarter end was in short-term and fixed maturities. More than 95% of the fixed income securities were 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.

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Accounting and Disclosure Changes

In May 2003, the Financial Accounting Standards Board (FASB) issued FAS Statement No. 150, Accounting for Certain Financial Instruments with Characteristics of both Liabilities and Equity. This Statement establishes standards for classifying and measuring as liabilities certain financial instruments that embody obligations of the issuer and have characteristics of both liabilities and equity.

Beginning third quarter 2003, in accordance with FAS 150, Aon will reclassify as liabilities its Redeemable Preferred Stock ($50 million) and Trust Preferred Capital Securities ($702 million). The amounts reclassified will be at fair value.

The difference between fair value and book value at July 1, 2003 will be reflected on the condensed consolidated statements of income as a cumulative effect of change in accounting principle, net of tax, in third quarter 2003. Changes in the fair value after July 1, 2003 will be reflected in interest expense. Dividends paid on the Capital Securities (currently shown as minority interest, net of tax on the condensed consolidated statements of income) and the Redeemable Preferred Stock will also be included in interest expense in future quarters.

Future Outlook

"We had solid organic revenue growth in the quarter and brokerage margins have improved year-over-year," Mr. Ryan said. "We have recruited some excellent new talent into our organization, and our franchise has never been stronger in terms of delivering valuable services and products to our clients. Margin expansion is a key focus, and we are working to improve margins in each of our operating segments."

Mr. Ryan added, "Based on our current outlook, we remain comfortable with a 2003 earnings per share range of $1.90 to $2.00, excluding unusual WTC charges and the impact of FAS 150."

The Company will host an audio webcast on Wednesday, August 6^th 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

			Second Quarter Ended								Six Months Ended
(millions except per share data)			Jun. 30, 2003			Jun. 30, 2002			Percent Change		Jun. 30, 2003			Jun. 30, 2002			Percent Change
Revenue
	Brokerage commissions and fees		$	1,713		$	1,510		13	%	$	3,389		$	2,954		15	%
	Premiums and other			635			638		—			1,267			1,173		8
	Investment income			90			(26	)	N/A			170			83		105
		Total revenue		2,438			2,122		15			4,826			4,210		15
Expenses
	General expenses			1,817			1,671		9			3,526			3,134		13
	Benefits to policyholders			325			391		(17	)		670			705		(5	)
	Interest expense			27			30		(10	)		55			59		(7	)
	Amortization of intangible assets			15			14		7			28			25		12
	Unusual charges—World Trade Center			9			—		N/A			46			—		N/A
		Total expenses		2,193			2,106		4			4,325			3,923		10
Income Before Income Tax and Minority Interest				245			16		+500			501			287		75
	Provision for income tax (37% in 2003 and 2002)			90			6		+500			185			107		73
Income Before Minority Interest				155			10		+500			316			180		76
	Minority interest—8.205% trust preferred capital securities			(9	)		(10	)	(10	)		(18	)		(20	)	(10	)
Net Income			$	146		$	—		N/A	%	$	298		$	160		86	%
	Preferred stock dividends			—			—		N/A			(1	)		(1	)	—
Net Income Available for Common Stockholders			$	146		$	—		N/A	%	$	297		$	159		87	%
Net Income Per Share:
	Basic net income per share		$	0.46		$	—		N/A	%	$	0.94		$	0.58		62	%
	Dilutive net income per share		$	0.46		$	—		N/A	%	$	0.94		$	0.57		65	%
	Dilutive average common and common equivalent shares outstanding			318.2			278.0		14	%		316.7			277.3		14	%

Aon Corporation
Segments

			Second Quarter Ended										Six Months Ended
(millions)			Jun. 30, 2003			Jun. 30, 2002			Percent Change		Organic Revenue Growth (5)		Jun. 30, 2003			Jun. 30, 2002			Percent Change		Organic Revenue Growth (5)
Revenue
Risk and insurance brokerage services (1)
	Risk management and insurance brokerage—Americas		$	590		$	517		14	%	14	%	$	1,097		$	965		14	%	13	%
	Risk management and insurance brokerage—International			507			413		23		10			1,031			833		24		10
	Reinsurance brokerage and related services			226			192		18		13			468			391		20		14
	Claims services			101			93		9		2			202			183		10		8
		Total risk and insurance brokerage services		1,424			1,215		17		11			2,798			2,372		18		12
Consulting (2)
	Benefits, compensation, management and communications consulting			224			194		15		5			433			377		15		6
	Human resource outsourcing			70			54		30		26			143			104		38		32
		Total consulting		294			248		19		9			576			481		20		11
Insurance underwriting (3)
	Accident & health and life			377			441		(15	)	(1	)		776			830		(7	)	2
	Warranty, credit and property & casualty			315			309		2		19			625			569		10		21
		Total insurance underwriting		692			750		(8	)	8			1,401			1,399		—		11
		Operating segments		2,410			2,213		9		10	%		4,775			4,252		12		11	%
Corporate and other				44			(91	)	N/A					79			(42	)	N/A
Intersegment revenues (4)				(16	)		—		N/A					(28	)		—		N/A
	Total revenue		$	2,438		$	2,122		15	%			$	4,826		$	4,210		15	%
Income (Loss) Before Income Tax and Minority Interest
	Risk and insurance brokerage services		$	175		$	144		22	%			$	405		$	333		22	%
	Consulting			21			23		(9	)				41			50		(18	)
	Insurance underwriting			64			2		+500					127			70		81
	Corporate and other			(15	)		(153	)	N/A					(72	)		(166	)	N/A
		Total income before income tax and minority interest	$	245		$	16		+500	%			$	501		$	287		75	%

(1)

Includes investment income of $20 million and $28 million for the second quarters ended June 30, 2003 and 2002, respectively, and $40 million and $49 million for the six months ended June 30, 2003 and 2002, respectively.

(2)

Includes investment income of $0 million for both the second quarters ended June 30, 2003 and 2002, respectively, and $1 million for both the six months ended June 30, 2003 and 2002, respectively.

(3)

Includes investment income of $30 million and $41 million, of which $1 million and $10 million pertain to interest earned on investments underlying investment-type contracts, for the second quarters ended June 30, 2003 and 2002, respectively. Includes investment income of $58 million and $83 million, of which $3 million and $22 million pertain to interest earned on investments underlying investment-type contracts, for the six months ended June 30, 2003 and 2002, respectively.

(4)

Total revenue from operating segments include intersegment revenues of $16 million and $28 million for the second quarter and six months ended June 30, 2003, respectively, 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 as the amounts were immaterial.

(5)

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

Aon Corporation
Corporate and Other

			Second Quarter Ended								Six Months Ended
(millions)			Jun. 30, 2003			Jun. 30, 2002			Percent Change		Jun. 30, 2003			Jun. 30, 2002			Percent Change
Revenue
Investment Income:
	Income from marketable equity securities and other investments (1)		$	36		$	3		+500	%	$	89		$	6		+500	%
	Limited partnership investments			—			5		(100	)		—			14		(100	)
	Interest on tax refund			—			—		N/A			—			48		(100	)
	Net gain (loss) on disposals and related expenses (2)			4			(103	)	N/A			(18	)		(118	)	N/A
		Total investment income		40			(95	)	N/A			71			(50	)	N/A
Auto finance service revenue				4			4		—			8			8		—
		Total revenue		44			(91	)	N/A			79			(42	)	N/A
Expenses
	General expenses (3)			23			32		(28	)		50			65		(23	)
	Interest expense			27			30		(10	)		55			59		(7	)
	Unusual charges—World Trade Center			9			—		N/A			46			—		N/A
		Total expenses		59			62		(5	)		151			124		22
Loss before income tax			$	(15	)	$	(153	)	N/A	%	$	(72	)	$	(166	)	N/A	%

(1)

Includes income of $21 million and $66 million from an increase in the value of warrants held by the company in Endurance Specialty for the second quarter and six months ended June 30, 2003, respectively, as well as $13 million and $20 million from a common equity interest in Endurance for the second quarter and six months ended June 30, 2003, respectively.

(2)

Includes impairment writedowns of $5 million and $101 million (including $56 million for the cumulative adjustment for other than temporary impairments that existed in prior financial reporting periods, of which $5 million pertained to first quarter 2002) for the second quarters ended June 30, 2003 and 2002, respectively, and $33 million and $109 million (including $51 million cumulative adjustment relating to prior financial reporting periods) for the six months ended June 30, 2003 and 2002, respectively.

(3)

Includes costs related to the auto finance service business of $13 million and $10 million for the second quarters ended June 30, 2003 and 2002, respectively, and $24 million and $20 million for the six months ended June 30, 2003 and 2002, respectively.

Aon Corporation
Supplemental Financial Information

			Second Quarter Ended
(millions)			Jun. 30, 2003			Jun. 30, 2002			Percent Change		Less: Currency Impact		Less: All Other (1)		Organic Revenue Growth
Revenue
Risk and insurance brokerage services
	Risk management and insurance brokerage—Americas		$	590		$	517		14	%	—	%	—	%	14	%
	Risk management and insurance brokerage—International			507			413		23		14		(1	)	10
	Reinsurance brokerage and related services			226			192		18		7		(2	)	13
	Claims services			101			93		9		3		4		2
		Total risk and insurance brokerage services		1,424			1,215		17		6		—		11
Consulting
	Benefits, compensation, management and communications consulting			224			194		15		5		5		5
	Human resource outsourcing			70			54		30		3		1		26
		Total consulting		294			248		19		5		5		9
Insurance underwriting
	Accident & health and life			377			441		(15	)	4		(18	)	(1	)
	Warranty, credit and property & casualty			315			309		2		3		(20	)	19
		Total insurance underwriting		692			750		(8	)	3		(19	)	8
		Operating segments		2,410			2,213		9		5	%	(6	)%	10	%
	Corporate and other			44			(91	)	N/A
Intersegment revenues				(16	)		—		N/A
	Total revenue		$	2,438		$	2,122		15	%
			Six Months Ended
(millions)			Jun. 30, 2003			Jun. 30, 2002			Percent Change		Less: Currency Impact		Less: All Other (1)		Organic Revenue Growth
Revenue
Risk and insurance brokerage services
	Risk management and insurance brokerage—Americas		$	1,097		$	965		14	%	—	%	1	%	13	%
	Risk management and insurance brokerage—International			1,031			833		24		14		—		10
	Reinsurance brokerage and related services			468			391		20		7		(1	)	14
	Claims services			202			183		10		3		(1	)	8
		Total risk and insurance brokerage services		2,798			2,372		18		6		—		12
Consulting
	Benefits, compensation, management and communications consulting			433			377		15		5		4		6
	Human resource outsourcing			143			104		38		3		3		32
		Total consulting		576			481		20		5		4		11
Insurance underwriting
	Accident & health and life			776			830		(7	)	3		(12	)	2
	Warranty, credit and property & casualty			625			569		10		4		(15	)	21
		Total insurance underwriting		1,401			1,399		—		3		(14	)	11
	Operating segments			4,775			4,252		12		5	%	(4	)%	11	%
Corporate and other				79			(42	)	N/A
Intersegment revenues				(28	)		—		N/A
	Total revenue		$	4,826		$	4,210		15	%

(1)

Includes items discussed in the organic revenue growth description, beyond currency impacts.

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Exhibit 99.1

Aon Reports Second Quarter and Six Months 2003 Results