Allied World Assurance 8-K Results of Operations and Financial Condition

Exhibit 99.1

ALLIED WORLD ASSURANCE COMPANY HOLDINGS, LTD

New Segment Financial Supplement

Investor Contact:	This report is for informational purposes only. It should be read in conjunction with documents filed by Allied
Keith Lennox	World Assurance Company Holdings, Ltd with the U.S. Securities and Exchange Commission.

Phone: (646) 794-0750
email: keith.lennox@awac.com

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

Any forward-looking statements made in this report reflect our current views with respect to future events and financial performance and are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Such statements involve risks and uncertainties, which may cause actual results to differ materially from those set forth in these statements. For example, our forward-looking statements could be affected by the ability to recognize the benefits of the Darwin Professional Underwriters, Inc. acquisition; pricing and policy term trends; increased competition; the impact of acts of terrorism and acts of war; greater frequency or severity of unpredictable catastrophic events; investigations of market practices and related settlement terms; negative rating agency actions; the adequacy of our loss reserves; the company or its subsidiaries becoming subject to significant income taxes in the United States or elsewhere; changes in regulations or tax laws; changes in the availability, cost or quality of reinsurance or retrocessional coverage; adverse general economic conditions including those related to the ongoing financial crisis; and judicial, legislative, political and other governmental developments, as well as management’s response to these factors, and other factors identified in our filings with the U.S. Securities and Exchange Commission. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date on which they are made. We are under no obligation (and expressly disclaim any such obligation) to update or revise any forward-looking statement that may be made from time to time, whether as a result of new information, future developments or otherwise.

ALLIED WORLD ASSURANCE COMPANY HOLDINGS, LTD
FINANCIAL SUPPLEMENT TABLE OF CONTENTS

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Basis of Presentation	4
- Consolidated Segment Results — Three months ended March 31, 2008	5
- Consolidated Segment Results — Three months ended June 30, 2008	6
- Consolidated Segment Results — Six months ended June 30, 2008	7
- Consolidated Segment Results — Three months ended September 30, 2008	8
- Consolidated Segment Results — Nine months ended September 30, 2008	9
- Consolidated Segment Results — Three months ended December 31, 2008	10
- Consolidated Segment Results — Year ended December 31, 2008	11

ALLIED WORLD ASSURANCE COMPANY HOLDINGS, LTD
BASIS OF PRESENTATION

PRESENTATION

• The following schedules show the company’s results of operations for each of its operating segments for all periods in 2008, recast under the new segment format. During the first quarter of 2009, the company realigned its management reporting structure due to organizational changes and the growth of its direct specialty insurance operations in the United States, including the recent acquisition of Darwin Professional Underwriters, Inc., and an increasing emphasis on markets served and customer focus. As a result, management monitors the performance of the company’s direct underwriting operations based on the geographic location of the company’s offices, the markets and customers served, and the type of accounts written. There were no changes to how management monitors the company’s reinsurance underwriting operations. The company is currently organized into three operating segments: U.S. insurance, international insurance and reinsurance. The 2008 results of operations reported under the “Reinsurance” and “Consolidated Totals” columns in the following schedules have not changed as a result of the new segment format.

• All financial information contained herein is unaudited.

• Unless otherwise noted, all data is in thousands of U.S. dollars, except for ratio information.

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ALLIED WORLD ASSURANCE COMPANY HOLDINGS, LTD
UNAUDITED CONSOLIDATED SEGMENT RESULTS
FOR THE THREE MONTHS ENDED MARCH 31, 2008

	U.S.			INTERNATIONAL						CONSOLIDATED
	INSURANCE			INSURANCE			REINSURANCE			TOTALS
Revenues
Gross premiums written	$	35,822		$	171,301		$	189,751		$	396,874
Net premiums written	$	23,119		$	114,112		$	189,341		$	326,572
Net premiums earned	$	30,043		$	122,653		$	120,376		$	273,072
Total revenues	$	30,043		$	122,653		$	120,376		$	273,072
Expenses
Net losses and loss expenses:
Current year	$	21,024		$	97,179		$	78,408		$	196,611
Prior years		(4,941	)		(25,400	)		(22,773	)		(53,114	)
Total net losses and loss expenses	$	16,083		$	71,779		$	55,635		$	143,497
Acquisition costs		2,985			834			23,021			26,840
General and administrative expenses		14,568			19,634			9,069			43,271
Total expenses	$	33,636		$	92,247		$	87,725		$	213,608
Underwriting (loss) income	$	(3,593	)	$	30,406		$	32,651		$	59,464
Net investment income											76,931
Net realized investment gains											3,465
Interest expense											(9,510	)
Foreign exchange loss											(476	)
Income before income taxes										$	129,874
GAAP Ratios
Loss and loss expense ratio		53.5	%		58.5	%		46.2	%		52.5	%
Acquisition cost ratio		9.9	%		0.7	%		19.1	%		9.8	%
General and administrative expense ratio		48.5	%		16.0	%		7.5	%		15.9	%
Expense ratio		58.4	%		16.7	%		26.6	%		25.7	%
Combined ratio		111.9	%		75.2	%		72.8	%		78.2	%

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ALLIED WORLD ASSURANCE COMPANY HOLDINGS, LTD
UNAUDITED CONSOLIDATED SEGMENT RESULTS
FOR THE THREE MONTHS ENDED JUNE 30, 2008

	U.S.			INTERNATIONAL						CONSOLIDATED
	INSURANCE			INSURANCE			REINSURANCE			TOTALS
Revenues
Gross premiums written	$	65,664		$	244,521		$	136,599		$	446,784
Net premiums written	$	35,644		$	147,980		$	136,626		$	320,250
Net premiums earned	$	31,681		$	118,087		$	119,108		$	268,876
Total revenues	$	31,681		$	118,087		$	119,108		$	268,876
Expenses
Net losses and loss expenses:
Current year	$	25,022		$	117,110		$	75,727		$	217,859
Prior years		(2,042	)		(35,733	)		(2,000	)		(39,775	)
Total net losses and loss expenses	$	22,980		$	81,377		$	73,727		$	178,084
Acquisition costs		2,632			(379	)		24,012			26,265
General and administrative expenses		14,275			20,974			11,131			46,380
Total expenses	$	39,887		$	101,972		$	108,870		$	250,729
Underwriting (loss) income	$	(8,206	)	$	16,115		$	10,238		$	18,147
Net investment income											72,345
Net realized investment losses											(4,393	)
Interest expense											(9,513	)
Foreign exchange gain											399
Income before income taxes										$	76,985
GAAP Ratios
Loss and loss expense ratio		72.5	%		68.9	%		61.9	%		66.2	%
Acquisition cost ratio		8.3	%		(0.3	%)		20.2	%		9.8	%
General and administrative expense ratio		45.1	%		17.8	%		9.3	%		17.2	%
Expense ratio		53.4	%		17.5	%		29.5	%		27.0	%
Combined ratio		125.9	%		86.4	%		91.4	%		93.2	%

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ALLIED WORLD ASSURANCE COMPANY HOLDINGS, LTD
UNAUDITED CONSOLIDATED SEGMENT RESULTS
FOR THE SIX MONTHS ENDED JUNE 30, 2008

	U.S.			INTERNATIONAL						CONSOLIDATED
	INSURANCE			INSURANCE			REINSURANCE			TOTALS
Revenues
Gross premiums written	$	101,486		$	415,821		$	326,350		$	843,657
Net premiums written	$	58,763		$	262,093		$	325,966		$	646,822
Net premiums earned	$	61,724		$	240,739		$	239,485		$	541,948
Total revenues	$	61,724		$	240,739		$	239,485		$	541,948
Expenses
Net losses and loss expenses:
Current year	$	46,046		$	214,289		$	154,135		$	414,470
Prior years		(6,983	)		(61,133	)		(24,773	)		(92,889	)
Total net losses and loss expenses	$	39,063		$	153,156		$	129,362		$	321,581
Acquisition costs		5,617			455			47,033			53,105
General and administrative expenses		28,843			40,608			20,200			89,651
Total expenses	$	73,523		$	194,219		$	196,595		$	464,337
Underwriting (loss) income	$	(11,799	)	$	46,520		$	42,890		$	77,611
Net investment income											149,276
Net realized investment losses											(928	)
Interest expense											(19,023	)
Foreign exchange loss											(77	)
Income before income taxes										$	206,859
GAAP Ratios
Loss and loss expense ratio		63.3	%		63.6	%		54.0	%		59.3	%
Acquisition cost ratio		9.1	%		0.2	%		19.6	%		9.8	%
General and administrative expense ratio		46.7	%		16.9	%		8.4	%		16.5	%
Expense ratio		55.8	%		17.1	%		28.0	%		26.3	%
Combined ratio		119.1	%		80.7	%		82.0	%		85.6	%

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ALLIED WORLD ASSURANCE COMPANY HOLDINGS, LTD
UNAUDITED CONSOLIDATED SEGMENT RESULTS
FOR THE THREE MONTHS ENDED SEPTEMBER 30, 2008

	U.S.			INTERNATIONAL						CONSOLIDATED
	INSURANCE			INSURANCE			REINSURANCE			TOTALS
Revenues
Gross premiums written	$	64,828		$	132,612		$	93,541		$	290,981
Net premiums written	$	45,674		$	95,943		$	92,286		$	233,903
Net premiums earned	$	32,034		$	116,377		$	123,562		$	271,973
Total revenues	$	32,034		$	116,377		$	123,562		$	271,973
Expenses
Net losses and loss expenses:
Current year	$	33,718		$	141,904		$	97,336		$	272,958
Prior years		(3,990	)		(53,576	)		(39,382	)		(96,948	)
Total net losses and loss expenses	$	29,728		$	88,328		$	57,954		$	176,010
Acquisition costs		2,852			1,794			23,969			28,615
General and administrative expenses		10,609			18,483			11,702			40,794
Total expenses	$	43,189		$	108,605		$	93,625		$	245,419
Underwriting (loss) income	$	(11,155	)	$	7,772		$	29,937		$	26,554
Net investment income											76,916
Net realized investment losses											(151,876	)
Interest expense											(9,515	)
Foreign exchange gain											2,728
Loss before income taxes										$	(55,193	)
GAAP Ratios
Loss and loss expense ratio		92.8	%		75.9	%		46.9	%		64.7	%
Acquisition cost ratio		8.9	%		1.5	%		19.4	%		10.5	%
General and administrative expense ratio		33.1	%		15.9	%		9.5	%		15.0	%
Expense ratio		42.0	%		17.4	%		28.9	%		25.5	%
Combined ratio		134.8	%		93.3	%		75.8	%		90.2	%

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ALLIED WORLD ASSURANCE COMPANY HOLDINGS, LTD
UNAUDITED CONSOLIDATED SEGMENT RESULTS
FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2008

	U.S.			INTERNATIONAL						CONSOLIDATED
	INSURANCE			INSURANCE			REINSURANCE			TOTALS
Revenues
Gross premiums written	$	166,314		$	548,433		$	419,891		$	1,134,638
Net premiums written	$	104,437		$	358,036		$	418,252		$	880,725
Net premiums earned	$	93,758		$	357,116		$	363,047		$	813,921
Total revenues	$	93,758		$	357,116		$	363,047		$	813,921
Expenses
Net losses and loss expenses:
Current year	$	79,764		$	356,193		$	251,471		$	687,428
Prior years		(10,973	)		(114,709	)		(64,155	)		(189,837	)
Total net losses and loss expenses	$	68,791		$	241,484		$	187,316		$	497,591
Acquisition costs		8,469			2,249			71,002			81,720
General and administrative expenses		39,452			59,091			31,902			130,445
Total expenses	$	116,712		$	302,824		$	290,220		$	709,756
Underwriting (loss) income	$	(22,954	)	$	54,292		$	72,827		$	104,165
Net investment income											226,192
Net realized investment losses											(152,804	)
Interest expense											(28,538	)
Foreign exchange gain											2,651
Income before income taxes										$	151,666
GAAP Ratios
Loss and loss expense ratio		73.4	%		67.6	%		51.6	%		61.1	%
Acquisition cost ratio		9.0	%		0.6	%		19.6	%		10.0	%
General and administrative expense ratio		42.1	%		16.5	%		8.8	%		16.0	%
Expense ratio		51.1	%		17.1	%		28.4	%		26.0	%
Combined ratio		124.5	%		84.7	%		80.0	%		87.1	%

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ALLIED WORLD ASSURANCE COMPANY HOLDINGS, LTD
UNAUDITED CONSOLIDATED SEGMENT RESULTS
FOR THE THREE MONTHS ENDED DECEMBER 31, 2008

	U.S.			INTERNATIONAL						CONSOLIDATED
	INSURANCE			INSURANCE			REINSURANCE			TOTALS
Revenues
Gross premiums written	$	153,671		$	147,025		$	10,249		$	310,945
Net premiums written	$	108,541		$	107,833		$	10,129		$	226,503
Net premiums earned	$	86,060		$	115,434		$	101,490		$	302,984
Other income	$	746		$	—		$	—		$	746
Total revenues	$	86,806		$	115,434		$	101,490		$	303,730
Expenses
Net losses and loss expenses:
Current year	$	60,046		$	101,015		$	72,728		$	233,789
Prior years		(25,474	)		(53,879	)		(10,905	)		(90,258	)
Total net losses and loss expenses	$	34,572		$	47,136		$	61,823		$	143,531
Acquisition costs		9,363			1,525			19,961			30,849
General and administrative expenses		28,069			16,399			11,647			56,115
Total expenses	$	72,004		$	65,060		$	93,431		$	230,495
Underwriting income	$	14,802		$	50,374		$	8,059		$	73,235
Net investment income											82,583
Net realized investment losses											(120,047	)
Interest expense											(10,205	)
Foreign exchange loss											(1,230	)
Income before income taxes										$	24,336
GAAP Ratios
Loss and loss expense ratio		40.2	%		40.8	%		60.9	%		47.4	%
Acquisition cost ratio		10.9	%		1.3	%		19.7	%		10.2	%
General and administrative expense ratio		32.6	%		14.2	%		11.5	%		18.5	%
Expense ratio		43.5	%		15.5	%		31.2	%		28.7	%
Combined ratio		83.7	%		56.3	%		92.1	%		76.1	%

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ALLIED WORLD ASSURANCE COMPANY HOLDINGS, LTD
UNAUDITED CONSOLIDATED SEGMENT RESULTS
FOR THE YEAR ENDED DECEMBER 31, 2008

	U.S.			INTERNATIONAL						CONSOLIDATED
	INSURANCE			INSURANCE			REINSURANCE			TOTALS
Revenues
Gross premiums written	$	319,985		$	695,459		$	430,140		$	1,445,584
Net premiums written	$	212,978		$	465,869		$	428,381		$	1,107,228
Net premiums earned	$	179,818		$	472,550		$	464,537		$	1,116,905
Other income	$	746		$	—		$	—		$	746
Total revenues	$	180,564		$	472,550		$	464,537		$	1,117,651
Expenses
Net losses and loss expenses:
Current year	$	139,810		$	457,208		$	324,199		$	921,217
Prior years		(36,447	)		(168,588	)		(75,060	)		(280,095	)
Total net losses and loss expenses	$	103,363		$	288,620		$	249,139		$	641,122
Acquisition costs		17,832			3,774			90,963			112,569
General and administrative expenses		67,520			75,490			43,550			186,560
Total expenses	$	188,715		$	367,884		$	383,652		$	940,251
Underwriting (loss) income	$	(8,151	)	$	104,666		$	80,885		$	177,400
Net investment income											308,775
Net realized investment losses											(272,851	)
Interest expense											(38,743	)
Foreign exchange gain											1,421
Income before income taxes										$	176,002
GAAP Ratios
Loss and loss expense ratio		57.5	%		61.1	%		53.6	%		57.4	%
Acquisition cost ratio		9.9	%		0.8	%		19.6	%		10.1	%
General and administrative expense ratio		37.5	%		16.0	%		9.4	%		16.7	%
Expense ratio		47.4	%		16.8	%		29.0	%		26.8	%
Combined ratio		104.9	%		77.9	%		82.6	%		84.2	%

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