Exhibit 99.1

The
Chubb Corporation Reclassification of
Property and Casualty
Underwriting Results For the Three Months Ended
June 30, 2004

This report is for informational purposes only. It should be read in conjunction with documents filed by The Chubb Corporation with the Securities and Exchange Commission, including the most recent Annual Report on Form 10-K and Quarterly Reports on Form 10-Q.

THE CHUBB CORPORATION

Beginning with the first quarter of 2005, the reporting format for property and casualty underwriting results by line of business has been changed to more closely reflect the way the business is now managed. The new reporting format provides additional clarity in that all Professional Liability business is now reported in one line within Chubb Specialty Insurance, all commercial business is now reported in Chubb Commercial Insurance and Reinsurance Assumed (Chubb Re) is now reported as a separate business unit. For additional information, see the first quarter 2005 earnings release.

Property and casualty underwriting results for the second quarter of 2004 presented herein have been reclassified to conform to the new reporting format.

Definitions of Key Terms

Underwriting Income (Loss)

Management evaluates underwriting results separately from investment results. The underwriting operations consist of four separate business units: personal insurance, commercial insurance, specialty insurance and reinsurance assumed. Performance of the business units is based on statutory underwriting results. Statutory accounting principles differ in certain respects from generally accepted accounting principles (GAAP). Under statutory accounting principles, policy acquisition and other underwriting expenses are recognized immediately, not at the time premiums are earned. Statutory underwriting income (loss) is arrived at by reducing premiums earned by losses and loss expenses incurred and statutory underwriting expenses incurred.

Management uses underwriting results determined in accordance with GAAP, among other measures, to assess the overall performance of the underwriting operations. To convert statutory underwriting results to a GAAP basis, policy acquisition expenses are deferred and amortized over the period in which the related premiums are earned. Underwriting income (loss) determined in accordance with GAAP is defined as premiums earned less losses and loss expenses incurred and GAAP underwriting expenses incurred.

Combined Loss and Expense Ratio or Combined Ratio

The combined loss and expense ratio, expressed as a percentage, is the key measure of underwriting profitability. Management uses the combined loss and expense ratio calculated in accordance with statutory accounting principles applicable to property and casualty insurance companies to evaluate the performance of the underwriting operations. It is the sum of the ratio of losses and loss expenses to premiums earned (loss ratio) plus the ratio of statutory underwriting expenses to premiums written (expense ratio) after reducing both premium amounts by dividends to policyholders.

THE CHUBB CORPORATION — WORLDWIDE
RECLASSIFICATION OF PROPERTY AND CASUALTY UNDERWRITING RESULTS
FOR THE THREE MONTHS ENDED JUNE 30, 2005 AND 2004
(MILLIONS OF DOLLARS)

	Personal								Other				Total
	Automobile				Homeowners				Personal				Personal
	2005	2004			2005	2004			2005	2004			2005	2004
Net Premiums Written		$	165.8			$	516.1			$	124.0			$	805.9
Increase (Decrease) in Unearned Premiums			16.3				53.8				(5.9	)			64.2
Net Premiums Earned			149.5				462.3				129.9				741.7
Net Losses Paid			85.0				254.2				67.3				406.5
Increase (Decrease) in Outstanding Losses			16.3				4.3				10.4				31.0
Net Losses Incurred			101.3				258.5				77.7				437.5
Expenses Incurred			43.6				162.1				40.7				246.4
Dividends Incurred			0.0				0.0				0.0				0.0
Statutory Underwriting Income (Loss)		$	4.6			$	41.7			$	11.5			$	57.8
Ratios After Dividends to Policyholders:
Loss			67.8	%			55.9	%			59.8	%			59.0	%
Expense			26.3				31.4				32.8				30.6
Combined			94.1	%			87.3	%			92.6	%			89.6	%
Premiums Written as a % of Total			5.6	%			17.6	%			4.3	%			27.5	%

The Property and Casualty underwriting results for 2004 reflect certain reclassifications to conform with the 2005 presentation. The worldwide totals are not affected.

Page 1 of 5

THE CHUBB CORPORATION — WORLDWIDE
RECLASSIFICATION OF PROPERTY AND CASUALTY UNDERWRITING RESULTS
FOR THE THREE MONTHS ENDED JUNE 30, 2005 AND 2004
(MILLIONS OF DOLLARS)

									Commercial				Commercial
	Commercial				Commercial				Workers’				Property				Total
	Multiple Peril				Casualty				Compensation				and Marine				Commercial
	2005	2004			2005	2004			2005	2004			2005	2004			2005	2004
Net Premiums Written		$	313.6			$	412.0			$	195.7			$	270.9			$	1,192.2
Increase (Decrease) in Unearned Premiums			1.8				20.2				(7.4	)			(0.4	)			14.2
Net Premiums Earned			311.8				391.8				203.1				271.3				1,178.0
Net Losses Paid			142.0				266.5				86.3				125.2				620.0
Increase (Decrease) in Outstanding Losses			(62.1	)			(46.6	)			46.4				(46.7	)			(109.0	)
Net Losses Incurred			79.9				219.9				132.7				78.5				511.0
Expenses Incurred			106.4				107.4				48.4				93.3				355.5
Dividends Incurred			0.0				0.0				6.8				0.0				6.8
Statutory Underwriting Income (Loss)		$	125.5			$	64.5			$	15.2			$	99.5			$	304.7
Ratios After Dividends to Policyholders:
Loss			25.6	%			56.1	%			67.6	%			28.9	%			43.6	%
Expense			34.0				26.1				25.6				34.5				30.0
Combined			59.6	%			82.2	%			93.2	%			63.4	%			73.6	%
Premiums Written as a % of Total			10.7	%			14.1	%			6.7	%			9.2	%			40.7	%

The Property and Casualty underwriting results for 2004 reflect certain reclassifications to conform with the 2005 presentation. The worldwide totals are not affected.

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THE CHUBB CORPORATION — WORLDWIDE
RECLASSIFICATION OF PROPERTY AND CASUALTY UNDERWRITING RESULTS
FOR THE THREE MONTHS ENDED JUNE 30, 2005 AND 2004
(MILLIONS OF DOLLARS)

	Professional								Total
	Liability				Surety				Specialty
	2005	2004			2005	2004			2005	2004
Net Premiums Written		$	619.6			$	45.5			$	665.1
Increase (Decrease) in Unearned Premiums			(11.0	)			0.9				(10.1	)
Net Premiums Earned			630.6				44.6				675.2
Net Losses Paid			303.7				2.2				305.9
Increase (Decrease) in Outstanding Losses			383.4				3.1				386.5
Net Losses Incurred			687.1				5.3				692.4
Expenses Incurred			155.7				17.2				172.9
Dividends Incurred			0.0				0.4				0.4
Statutory Underwriting Income (Loss)		$	(212.2	)		$	21.7			$	(190.5	)
Ratios After Dividends to Policyholders:
Loss			109.0	%			12.0	%			102.6	%
Expense			25.1				38.1				26.0
Combined			134.1	%			50.1	%			128.6	%
Premiums Written as a % of Total			21.1	%			1.6	%			22.7	%

The Property and Casualty underwriting results for 2004 reflect certain reclassifications to conform with the 2005 presentation. The worldwide totals are not affected.

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THE CHUBB CORPORATION — WORLDWIDE
RECLASSIFICATION OF PROPERTY AND CASUALTY UNDERWRITING RESULTS
FOR THE THREE MONTHS ENDED JUNE 30, 2005 AND 2004
(MILLIONS OF DOLLARS)

	Total				Reinsurance				Worldwide
	Insurance				Assumed				Total
	2005	2004			2005	2004			2005	2004
Net Premiums Written		$	2,663.2			$	266.4			$	2,929.6
Increase (Decrease) in Unearned Premiums			68.3				(0.3	)			68.0
Net Premiums Earned			2,594.9				266.7				2,861.6
Net Losses Paid			1,332.4				48.2				1,380.6
Increase (Decrease) in Outstanding Losses			308.5				116.8				425.3
Net Losses Incurred			1,640.9				165.0				1,805.9
Expenses Incurred			774.8				88.5				863.3
Dividends Incurred			7.2				0.0				7.2
Statutory Underwriting Income (Loss)		$	172.0			$	13.2				185.2
Increase in Deferred Acquisition Costs											9.8
GAAP Underwriting Income										$	195.0
Ratios After Dividends to Policyholders:
Loss			63.4	%			61.9	%			63.3	%
Expense			29.2				33.2				29.5
Combined			92.6	%			95.1	%			92.8	%
Premiums Written as a % of Total			90.9	%			9.1	%			100.0	%

The Property and Casualty underwriting results for 2004 reflect certain reclassifications to conform with the 2005 presentation. The worldwide totals are not affected.

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THE CHUBB CORPORATION — WORLDWIDE
RECLASSIFICATION OF PROPERTY AND CASUALTY UNDERWRITING RESULTS
FOR THE THREE MONTHS ENDED JUNE 30, 2005 AND 2004
(MILLIONS OF DOLLARS)

									Worldwide
	United States				Foreign				Total
	2005	2004			2005	2004			2005	2004
Net Premiums Written		$	2,430.2			$	499.4			$	2,929.6
Increase (Decrease) in Unearned Premiums			69.3				(1.3	)			68.0
Net Premiums Earned			2,360.9				500.7				2,861.6
Net Losses Paid			1,179.4				201.2				1,380.6
Increase (Decrease) in Outstanding Losses			323.6				101.7				425.3
Net Losses Incurred			1,503.0				302.9				1,805.9
Expenses Incurred			699.0				164.3				863.3
Dividends Incurred			7.2				0.0				7.2
Statutory Underwriting Income (Loss)		$	151.7			$	33.5				185.2
Increase in Deferred Acquisition Costs											9.8
GAAP Underwriting Income										$	195.0
Ratios After Dividends to Policyholders:
Loss			63.9	%			60.5	%			63.3	%
Expense			28.8				32.9				29.5
Combined			92.7	%			93.4	%			92.8	%
Premiums Written as a % of Total			83.0	%			17.0	%			100.0	%

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