Alterra Capital 8-K Results of Operations and Financial Condition

Exhibit 99.1

ALTERRA CAPITAL HOLDINGS LIMITED

Segment Re-presentation

(Unaudited)

This supplement is for information purposes only. It should be read in conjunction with documents filed by Alterra Capital

Holdings Limited with the U.S. Securities and Exchange Commission pursuant to the Securities Exchange Act 1934.

Alterra Capital Holdings Limited

Investors:

Susan Spivak Bernstein, +1-212-898-6640

or

Media:

Kekst and Company

Peter Hill or Melissa Sheer, +1-212-521-4800

ALTERRA CAPITAL HOLDINGS LIMITED

Effective January 1, 2012, Alterra Capital Holdings Limited (“the Company”) redefined its operating and reporting segments. Reinsurance business written within Latin America, which was previously reported within the reinsurance and Alterra at Lloyd’s segments, has been reclassified to a new Latin America segment. In addition, business written by the Company’s recently incorporated Brazilian reinsurance company, Alterra Resseguradora do Brasil Limitada (“Alterra Brazil”), will be included in the Latin America segment. Insurance business written by Alterra Insurance USA Inc., which was previously reported within the global insurance segment (formerly the insurance segment), has been reclassified to the U.S. insurance segment (formerly the U.S. specialty segment). Alterra Insurance USA Inc. is a managing general underwriter for Alterra Excess & Surplus Insurance Company and Alterra America Insurance Company, as well as various third party insurance companies, and is the Company’s principal insurance underwriting platform for retail distribution in the United States.

Segment disclosures for comparative periods have been re-presented to reflect these reclassifications between segments.

The Company monitors the performance of its underwriting operations in six segments: global insurance, U.S. insurance, reinsurance, Alterra at Lloyd’s, Latin America and life and annuity reinsurance.

Global Insurance Segment - The Company’s global insurance segment (formerly the insurance segment) offers property and casualty excess of loss insurance from its offices in Bermuda, Dublin and London primarily to Fortune 1000 companies. Principal lines of business include aviation, excess liability, professional liability and property.

U.S. Insurance Segment - The Company’s U.S. insurance segment (formerly the U.S. specialty segment) offers property and casualty insurance coverage from offices in the United States primarily to Fortune 3000 companies. Principal lines of business include general liability, marine, professional liability and property.

Reinsurance Segment - The Company’s reinsurance segment offers property and casualty quota share and excess of loss reinsurance from its offices in Bermuda, Dublin, London and the United States to insurance and reinsurance companies worldwide. Principal lines of business include agriculture, auto, aviation, credit/surety, general casualty, marine & energy, medical malpractice, professional liability, property, whole account and workers’ compensation.

Alterra at Lloyd’s Segment - The Company’s Alterra at Lloyd’s segment offers property and casualty quota share and excess of loss insurance and reinsurance from its offices in London, Dublin and Zurich primarily to medium to large sized international clients. This segment comprises the Company’s proportionate share of the underwriting results of Lloyd’s Syndicates 1400, 2525, and 2526 (collectively, the “Syndicates”), and the results of Alterra at Lloyd’s, the managing agent for Syndicate 1400. The Syndicates underwrite a diverse portfolio of specialty risks, including accident & health, aviation, financial institutions, international casualty, marine, professional liability and property.

Latin America Segment -The Company’s Latin America segment offers property and casualty quota share and excess of loss reinsurance from its offices in Rio de Janeiro, Bogota and Buenos Aires. Principal lines of business include aviation, general liability, marine, property and surety.

Life and Annuity Reinsurance Segment - The Company’s life and annuity reinsurance segment operates out of Bermuda and offers reinsurance products focusing on blocks of life and annuity business, which take the form of co-insurance transactions whereby the risks are reinsured on the same basis as the original policies. The Company has determined not to write any new life and annuity contracts in the foreseeable future.

ALTERRA CAPITAL HOLDINGS LIMITED

SCHEDULE OF SUPPLEMENTAL UNDERWRITING DATA–YEAR ENDED DECEMBER 31, 2011 (Unaudited) - RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

	Property and Casualty																		Life & Annuity			Corporate			Consolidated
	Global Insurance			U.S. Insurance			Reinsurance			Alterra at Lloyd’s			Latin America			Total			Reinsurance
Gross premiums written	$	365,761		$	374,696		$	815,352		$	253,067		$	91,834		$	1,900,710		$	3,356		$	—			$1,904,066
Reinsurance premiums ceded		(181,454	)		(142,566	)		(75,652	)		(63,708	)		(8,332	)		(471,712	)		(365	)		—			(472,077)
Net premiums written	$	184,307		$	232,130		$	739,700		$	189,359		$	83,502		$	1,428,998		$	2,991		$	—		$	1,431,989
Earned premiums	$	364,087		$	337,041		$	861,637		$	224,665		$	55,051		$	1,842,481		$	3,356		$	—		$	1,845,837
Earned premiums ceded		(175,348	)		(113,718	)		(66,580	)		(60,922	)		(3,930	)		(420,498	)		(365	)		—			(420,863	)
Net premiums earned		188,739			223,323			795,057			163,743			51,121			1,421,983			2,991			—			1,424,974
Net losses and loss expenses		(91,753	)		(153,558	)		(511,947	)		(158,323	)		(30,012	)		(945,593	)		—			—			(945,593	)
Claims and policy benefits		—			—			—			—			—			—			(59,382	)		—			(59,382	)
Acquisition costs		517			(36,404	)		(174,514	)		(36,805	)		(13,339	)		(260,545	)		(557	)		—			(261,102	)
General and administrative expenses		(28,377	)		(45,171	)		(74,974	)		(31,304	)		(10,045	)		(189,871	)		(648	)		—			(190,519	)
Other income (loss)		686			279			1,225			1,204			—			3,394			382			—			3,776
Underwriting income (loss)		69,812			(11,531	)		34,847			(61,485	)		(2,275	)		29,368			n/a			—			n/a
Net investment income																				48,534			186,312			234,846
Net realized and unrealized losses on investments																				(10,408	)		(27,931	)		(38,339	)
Net impairment losses recognized in earnings																							(2,945	)		(2,945	)
Corporate other income																							1,620			1,620
Interest expense																							(43,688	)		(43,688	)
Net foreign exchange losses																							(1,312	)		(1,312	)
Corporate general and administrative expenses																							(66,555	)		(66,555	)
(Loss) income before taxes																			$	(19,088	)	$	45,501		$	55,781
Loss ratio [a]		48.6%			68.8%			64.4%			96.7%			58.7%			66.5%
Acquisition cost ratio [b]		(0.3%)			16.3%			21.9%			22.5%			26.1%			18.3%
General and administrative expense ratio [c]		15.0%			20.2%			9.4%			19.1%			19.6%			13.4%
Combined ratio [d]		63.4%			105.3%			95.8%			138.3%			104.5%			98.2%

[a] The loss ratio is calculated by dividing net losses and loss expenses by net premiums earned for the property & casualty business.

[b] The acquisition cost ratio is calculated by dividing acquisition costs by net premiums earned for the property & casualty business.

[c] The general and administrative expense ratio is calculated by dividing general and administrative expenses by net premiums earned for the property & casualty business.

[d] The combined ratio is calculated by dividing the sum of net losses and loss expenses, acquisition costs and general and administrative expenses by net premiums earned for the property & casualty business.

Percentage totals may not add due to rounding.

n/a—Not applicable.

n/m—Not meaningful.

ALTERRA CAPITAL HOLDINGS LIMITED

SCHEDULE OF SUPPLEMENTAL UNDERWRITING DATA–QUARTER ENDED MARCH 31, 2011 (Unaudited) - RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

	Property and Casualty																		Life & Annuity			Corporate			Consolidated
	Global Insurance			U.S. Insurance			Reinsurance			Alterra at Lloyd’s			Latin America			Total			Reinsurance
Gross premiums written	$	63,895		$	77,765		$	360,727		$	107,890		$	17,136		$	627,413		$	435		$	—		$	627,848
Reinsurance premiums ceded		(38,524	)		(38,317	)		(35,252	)		(23,179	)		(2,065	)		(137,337	)		(20	)		—			(137,357	)
Net premiums written	$	25,371		$	39,448		$	325,475		$	84,711		$	15,071		$	490,076		$	415		$	—		$	490,491
Earned premiums	$	90,651		$	81,470		$	244,340		$	63,164		$	9,202		$	488,827		$	435		$	—		$	489,262
Earned premiums ceded		(40,779	)		(27,801	)		(19,901	)		(20,580	)		(294	)		(109,355	)		(20	)		—			(109,375	)
Net premiums earned		49,872			53,669			224,439			42,584			8,908			379,472			415			—			379,887
Net losses and loss expenses		(31,624	)		(34,415	)		(183,908	)		(48,443	)		(6,016	)		(304,406	)		—			—			(304,406	)
Claims and policy benefits		—			—			—			—			—			—			(14,710	)		—			(14,710	)
Acquisition costs		(264	)		(7,986	)		(47,760	)		(12,652	)		(1,787	)		(70,449	)		(159	)		—			(70,608	)
General and administrative expenses		(7,952	)		(11,270	)		(22,272	)		(8,253	)		(2,456	)		(52,203	)		(177	)		—			(52,380	)
Other income (loss)		729			83			—			215			—			1,027			—			—			1,027
Underwriting income (loss)		10,761			81			(29,501	)		(26,549	)		(1,351	)		(46,559	)		n/a			—			n/a
Net investment income																				12,343			45,423			57,766
Net realized and unrealized gains (losses) on investments																				2,807			(21,625	)		(18,818	)
Net impairment losses recognized in earnings																							(1,029	)		(1,029	)
Corporate other income																							288			288
Interest expense																							(8,459	)		(8,459	)
Net foreign exchange gains																							878			878
Corporate general and administrative expenses																							(18,823	)		(18,823	)
Income (loss) before taxes																			$	519		$	(3,347	)	$	(49,387	)
Loss ratio		63.4	%		64.1	%		81.9	%		113.8	%		67.5	%		80.2	%
Acquisition cost ratio		0.5	%		14.9	%		21.3	%		29.7	%		20.1	%		18.6	%
General and administrative expense ratio		15.9	%		21.0	%		9.9	%		19.4	%		27.6	%		13.8	%
Combined ratio		79.9	%		100.0	%		113.1	%		162.8	%		115.2	%		112.5	%

ALTERRA CAPITAL HOLDINGS LIMITED

SCHEDULE OF SUPPLEMENTAL UNDERWRITING DATA–QUARTER ENDED JUNE 30, 2011 (Unaudited) - RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

	Property and Casualty																		Life & Annuity			Corporate			Consolidated
	Global Insurance			U.S. Insurance			Reinsurance			Alterra at Lloyd’s			Latin America			Total			Reinsurance
Gross premiums written	$	130,909		$	109,794		$	244,899		$	72,428		$	4,947		$	562,977		$	930		$	—		$	563,907
Reinsurance premiums ceded		(55,133	)		(28,227	)		(27,675	)		(24,918	)		(572	)		(136,525	)		(101	)		—			(136,626	)
Net premiums written	$	75,776		$	81,567		$	217,224		$	47,510		$	4,375		$	426,452		$	829		$	—		$	427,281
Earned premiums	$	88,892		$	82,244		$	203,470		$	58,117		$	9,355		$	442,078		$	930		$	—		$	443,008
Earned premiums ceded		(43,286	)		(23,835	)		(11,815	)		(14,540	)		(490	)		(93,966	)		(101	)		—			(94,067	)
Net premiums earned		45,606			58,409			191,655			43,577			8,865			348,112			829			—			348,941
Net losses and loss expenses		(23,689	)		(38,012	)		(122,576	)		(21,072	)		(5,784	)		(211,133	)		—			—			(211,133	)
Claims and policy benefits		—			—			—			—			—			—			(15,570	)		—			(15,570	)
Acquisition costs		1,117			(10,400	)		(42,947	)		(9,946	)		(2,382	)		(64,558	)		(122	)		—			(64,680	)
General and administrative expenses		(6,774	)		(11,374	)		(21,647	)		(7,773	)		(3,053	)		(50,621	)		(259	)		—			(50,880	)
Other income (loss)		85			54			548			165			—			852			(23	)		—			829
Underwriting income (loss)		16,345			(1,323	)		5,033			4,951			(2,354	)		22,652			n/a			—			n/a
Net investment income																				12,545			47,120			59,665
Net realized and unrealized losses on investments																				(1,299	)		(4,475	)		(5,774	)
Net impairment losses recognized in earnings																							(353	)		(353	)
Corporate other income																							(238	)		(238	)
Interest expense																							(10,630	)		(10,630	)
Net foreign exchange losses																							(3,090	)		(3,090	)
Corporate general and administrative expenses																							(18,779	)		(18,779	)
(Loss) income before taxes																			$	(3,899	)	$	9,555		$	28,308
Loss ratio		51.9	%		65.1	%		64.0	%		48.4	%		65.2	%		60.7	%
Acquisition cost ratio		(2.4	%)		17.8	%		22.4	%		22.8	%		26.9	%		18.5	%
General and administrative expense ratio		14.9	%		19.5	%		11.3	%		17.8	%		34.4	%		14.5	%
Combined ratio		64.3	%		102.4	%		97.7	%		89.0	%		126.6	%		93.7	%

ALTERRA CAPITAL HOLDINGS LIMITED

SCHEDULE OF SUPPLEMENTAL UNDERWRITING DATA–QUARTER ENDED SEPTEMBER 30, 2011 (Unaudited) - RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

	Property and Casualty																		Life & Annuity			Corporate			Consolidated
	Global Insurance			U.S. Insurance			Reinsurance			Alterra at Lloyd’s			Latin America			Total			Reinsurance
Gross premiums written	$	73,297		$	84,858		$	121,329		$	44,816		$	61,206		$	385,506		$	822		$	—		$	386,328
Reinsurance premiums ceded		(37,625	)		(30,579	)		(11,055	)		(6,723	)		(4,819	)		(90,801	)		(90	)		—			(90,891	)
Net premiums written	$	35,672		$	54,279		$	110,274		$	38,093		$	56,387		$	294,705		$	732		$	—		$	295,437
Earned premiums	$	93,467		$	83,279		$	206,698		$	50,534		$	18,131		$	452,109		$	822		$	—		$	452,931
Earned premiums ceded		(48,456	)		(28,004	)		(17,146	)		(10,850	)		(1,343	)		(105,799	)		(90	)		—			(105,889	)
Net premiums earned		45,011			55,275			189,552			39,684			16,788			346,310			732			—			347,042
Net losses and loss expenses		(21,288	)		(36,002	)		(108,135	)		(24,462	)		(8,634	)		(198,521	)		—			—			(198,521	)
Claims and policy benefits		—			—			—			—			—			—			(14,538	)		—			(14,538	)
Acquisition costs		748			(9,669	)		(41,781	)		(6,230	)		(4,357	)		(61,289	)		(145	)		—			(61,434	)
General and administrative expenses		(6,699	)		(10,228	)		(16,470	)		(8,007	)		(2,431	)		(43,835	)		(145	)		—			(43,980	)
Other income (loss)		—			58			777			(27	)		—			808			(8	)		—			800
Underwriting income (loss)		17,772			(566	)		23,943			958			1,366			43,473			n/a			—			n/a
Net investment income																				12,131			48,204			60,335
Net realized and unrealized losses on investments																				(6,407	)		(1,565	)		(7,972	)
Net impairment losses recognized in earnings																							(861	)		(861	)
Corporate other income																							673			673
Interest expense																							(11,303	)		(11,303	)
Net foreign exchange gains																							147			147
Corporate general and administrative expenses																							(17,575	)		(17,575	)
(Loss) income before taxes																			$	(8,380	)	$	17,720		$	52,813
Loss ratio		47.3	%		65.1	%		57.0	%		61.6	%		51.4	%		57.3	%
Acquisition cost ratio		(1.7	%)		17.5	%		22.0	%		15.7	%		26.0	%		17.7	%
General and administrative expense ratio		14.9	%		18.5	%		8.7	%		20.2	%		14.5	%		12.7	%
Combined ratio		60.5	%		101.1	%		87.8	%		97.5	%		91.9	%		87.7	%

ALTERRA CAPITAL HOLDINGS LIMITED

SCHEDULE OF SUPPLEMENTAL UNDERWRITING DATA–QUARTER ENDED DECEMBER 31, 2011 (Unaudited) - RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

	Property and Casualty																		Life & Annuity			Corporate			Consolidated
	Global Insurance			U.S. Insurance			Reinsurance			Alterra at Lloyd’s			Latin America			Total			Reinsurance
Gross premiums written	$	97,660		$	102,279		$	88,397		$	27,933		$	8,545		$	324,814		$	1,169		$	—		$	325,983
Reinsurance premiums ceded		(50,172	)		(45,443	)		(1,670	)		(8,888	)		(876	)		(107,049	)		(154	)		—			(107,203	)
Net premiums written	$	47,488		$	56,836		$	86,727		$	19,045		$	7,669		$	217,765		$	1,015		$	—		$	218,780
Earned premiums	$	91,077		$	90,048		$	207,129		$	52,850		$	18,363		$	459,467		$	1,169		$	—		$	460,636
Earned premiums ceded		(42,827	)		(34,078	)		(17,718	)		(14,952	)		(1,803	)		(111,378	)		(154	)		—			(111,532	)
Net premiums earned		48,250			55,970			189,411			37,898			16,560			348,089			1,015			—			349,104
Net losses and loss expenses		(15,152	)		(45,129	)		(97,328	)		(64,346	)		(9,578	)		(231,533	)		—			—			(231,533	)
Claims and policy benefits		—			—			—			—			—			—			(14,564	)		—			(14,564	)
Acquisition costs		(1,084	)		(8,349	)		(42,026	)		(7,977	)		(4,813	)		(64,249	)		(131	)		—			(64,380	)
General and administrative expenses		(6,952	)		(12,299	)		(14,585	)		(7,271	)		(2,105	)		(43,212	)		(67	)		—			(43,279	)
Other income (loss)		(128	)		84			(100	)		851			—			707			413			—			1,120
Underwriting income (loss)		24,934			(9,723	)		35,372			(40,845	)		64			9,802			n/a			—			n/a
Net investment income																				11,515			45,565			57,080
Net realized and unrealized losses on investments																				(5,509	)		(266	)		(5,775	)
Net impairment losses recognized in earnings																							(702	)		(702	)
Corporate other income																							897			897
Interest expense																							(13,296	)		(13,296	)
Net foreign exchange gains																							753			753
Corporate general and administrative expenses																							(11,378	)		(11,378	)
(Loss) income before taxes																			$	(7,328	)	$	21,573		$	24,047
Loss ratio		31.4	%		80.6	%		51.4	%		169.8	%		57.8	%		66.5	%
Acquisition cost ratio		2.2	%		14.9	%		22.2	%		21.0	%		29.1	%		18.5	%
General and administrative expense ratio		14.4	%		22.0	%		7.7	%		19.2	%		12.7	%		12.4	%
Combined ratio		48.1	%		117.5	%		81.3	%		210.0	%		99.6	%		97.4	%

ALTERRA CAPITAL HOLDINGS LIMITED

SCHEDULE OF SUPPLEMENTAL UNDERWRITING DATA–YEAR ENDED DECEMBER 31, 2010 (Unaudited) - RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

	Property and Casualty																		Life & Annuity			Corporate			Consolidated
	Global Insurance			U.S. Insurance			Reinsurance			Alterra  at Lloyd’s			Latin America			Total			Reinsurance
Gross premiums written	$	370,120		$	323,990		$	487,100		$	179,774		$	44,812		$	1,405,796		$	4,935		$	—		$	1,410,731
Reinsurance premiums ceded		(170,608	)		(98,576	)		(63,991	)		(37,448	)		(140	)		(370,763	)		(400	)		—			(371,163	)
Net premiums written	$	199,512		$	225,414		$	423,109		$	142,326		$	44,672		$	1,035,033		$	4,535		$	—		$	1,039,568
Earned premiums	$	391,716		$	311,950		$	692,303		$	164,648		$	13,095		$	1,573,712		$	4,935		$	—		$	1,578,647
Earned premiums ceded		(173,123	)		(125,218	)		(71,596	)		(35,793	)		(31	)		(405,761	)		(400	)		—			(406,161	)
Net premiums earned		218,593			186,732			620,707			128,855			13,064			1,167,951			4,535			—			1,172,486
Net losses and loss expenses		(128,823	)		(118,337	)		(344,063	)		(55,190	)		(8,428	)		(654,841	)		—			—			(654,841	)
Claims and policy benefits		—			—			—			—						—			(65,213	)		—			(65,213	)
Acquisition costs		(3,381	)		(28,444	)		(129,242	)		(22,447	)		(3,589	)		(187,103	)		(361	)		—			(187,464	)
General and administrative expenses		(28,615	)		(36,015	)		(62,730	)		(23,965	)		(7,909	)		(159,234	)		(2,964	)		—			(162,198	)
Other income (loss)		760			507			—			2,534			—			3,801			286			—			4,087
Underwriting income (loss)		58,534			4,443			84,672			29,787			(6,862	)		170,574			n/a			—			n/a
Net investment income																				49,785			172,673			222,458
Net realized and unrealized gains on investments																				11,358			5,514			16,872
Net impairment losses recognized in earnings																							(2,645	)		(2,645	)
Corporate other income																							721			721
Interest expense																							(28,275	)		(28,275	)
Net foreign exchange gains																							115			115
Merger and acquisition expenses																							48,776			48,776
Corporate general and administrative expenses																							(58,388	)		(58,388	)
(Loss) income before taxes																			$	(2,574	)	$	138,491		$	306,491
Loss ratio		58.9	%		63.4	%		55.4	%		42.8	%		64.5	%		56.1	%
Acquisition cost ratio		1.5	%		15.2	%		20.8	%		17.4	%		27.5	%		16.0	%
General and administrative expense ratio		13.1	%		19.3	%		10.1	%		18.6	%		60.5	%		13.6	%
Combined ratio		73.6	%		97.9	%		86.4	%		78.8	%		152.5	%		85.7	%

ALTERRA CAPITAL HOLDINGS LIMITED

SCHEDULE OF SUPPLEMENTAL UNDERWRITING DATA–QUARTER ENDED MARCH 31, 2010 (Unaudited) - RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

	Property and Casualty																		Life & Annuity			Corporate			Consolidated
	Global Insurance			U.S. Insurance			Reinsurance			Alterra at Lloyd’s			Latin America			Total			Reinsurance
Gross premiums written	$	66,421		$	76,887		$	154,829		$	72,117		$	22		$	370,276		$	863		$	—		$	371,139
Reinsurance premiums ceded		(38,576	)		(49,227	)		(45,351	)		(19,959	)		—			(153,113	)		(107	)		—			(153,220	)
Net premiums written	$	27,845		$	27,660		$	109,478		$	52,158		$	22		$	217,163		$	756		$	—		$	217,919
Earned premiums	$	97,041		$	73,890		$	95,737		$	37,460		$	6		$	304,134		$	863		$	—		$	304,997
Earned premiums ceded		(47,246	)		(39,977	)		(15,958	)		(7,469	)		—			(110,650	)		(107	)		—			(110,757	)
Net premiums earned		49,795			33,913			79,779			29,991			6			193,484			756			—			194,240
Net losses and loss expenses		(37,279	)		(21,363	)		(50,061	)		(16,258	)		(4	)		(124,965	)		—			—			(124,965	)
Claims and policy benefits		—			—			—			—			—			—			(17,659	)		—			(17,659	)
Acquisition costs		309			(3,674	)		(14,965	)		(5,767	)		(1	)		(24,098	)		(146	)		—			(24,244	)
General and administrative expenses		(5,897	)		(8,472	)		(7,832	)		(2,713	)		(1,127	)		(26,041	)		(657	)		—			(26,698	)
Other income (loss)		(11	)		5			—			178			—			172			(28	)		—			144
Underwriting income (loss)		6,917			409			6,921			5,431			(1,126	)		18,552			n/a			—			n/a
Net investment income																				13,099			35,291			48,390
Net realized and unrealized gains on investments																				5,916			506			6,422
Net impairment losses recognized in earnings																							(420	)		(420	)
Corporate other income																							200			200
Interest expense																							(4,942	)		(4,942	)
Net foreign exchange gains																							2,452			2,452
Merger and acquisition expenses																							(4,744	)		(4,744	)
Corporate general and administrative expenses																							(9,830	)		(9,830	)
Income before taxes																			$	1,281		$	18,513		$	38,346
Loss ratio		74.9	%		63.0	%		62.7	%		54.2	%		66.7	%		64.6	%
Acquisition cost ratio		(0.6	%)		10.8	%		18.8	%		19.2	%		16.7	%		12.5	%
General and administrative expense ratio		11.8	%		25.0	%		9.8	%		9.0	%		n/m			13.5	%
Combined ratio		86.1	%		98.8	%		91.3	%		82.5	%		n/m			90.5	%

ALTERRA CAPITAL HOLDINGS LIMITED

SCHEDULE OF SUPPLEMENTAL UNDERWRITING DATA–QUARTER ENDED JUNE 30, 2010 (Unaudited) - RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

	Property and Casualty																		Life & Annuity			Corporate			Consolidated
	Global Insurance			U.S. Insurance			Reinsurance			Alterra at Lloyd’s			Latin America			Total			Reinsurance
Gross premiums written	$	132,312		$	97,487		$	117,614		$	41,308		$	9,458		$	398,179		$	802		$	—		$	398,981
Reinsurance premiums ceded		(46,257	)		(6,852	)		(13,348	)		(13,233	)		—			(79,690	)		(25	)		—			(79,715	)
Net premiums written	$	86,055		$	90,635		$	104,266		$	28,075		$	9,458		$	318,489		$	777		$	—		$	319,266
Earned premiums	$	99,874		$	76,032		$	174,442		$	40,195		$	378		$	390,921		$	802		$	—		$	391,723
Earned premiums ceded		(43,676	)		(28,588	)		(19,054	)		(7,120	)		—			(98,438	)		(25	)		—			(98,463	)
Net premiums earned		56,198			47,444			155,388			33,075			378			292,483			777			—			293,260
Net losses and loss expenses		(35,927	)		(29,052	)		(82,278	)		(12,322	)		(238	)		(159,817	)		—			—			(159,817	)
Claims and policy benefits		—			—			—			—			—			—			(13,943	)		—			(13,943	)
Acquisition costs		(797	)		(9,135	)		(32,604	)		(6,059	)		(80	)		(48,675	)		(123	)		—			(48,798	)
General and administrative expenses		(6,501	)		(7,986	)		(13,975	)		(4,717	)		(1,954	)		(35,133	)		(642	)		—			(35,775	)
Other income (loss)		—			97			155			173			—			425			—			—			425
Underwriting income (loss)		12,973			1,368			26,686			10,150			(1,894	)		49,283			n/a			—			n/a
Net investment income																				12,420			40,857			53,277
Net realized and unrealized losses on investments																				(1,860	)		(12,926	)		(14,786	)
Net impairment losses recognized in earnings																							(300	)		(300	)
Corporate other income																							(150	)		(150	)
Interest expense																							(7,916	)		(7,916	)
Net foreign exchange gains																							634			634
Merger and acquisition expenses																							54,570			54,570
Corporate general and administrative expenses																							(14,874	)		(14,874	)
(Loss) income before taxes																			$	(3,371	)	$	59,895		$	105,807
Loss ratio		63.9	%		61.2	%		53.0	%		37.3	%		62.9	%		54.6	%
Acquisition cost ratio		1.4	%		19.3	%		21.0	%		18.3	%		21.2	%		16.6	%
General and administrative expense ratio		11.6	%		16.8	%		9.0	%		14.3	%		n/m			12.0	%
Combined ratio		76.9	%		97.3	%		82.9	%		69.8	%		n/m			83.3	%

ALTERRA CAPITAL HOLDINGS LIMITED

SCHEDULE OF SUPPLEMENTAL UNDERWRITING DATA–QUARTER ENDED SEPTEMBER 30, 2010 (Unaudited) - RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

	Property and Casualty																		Life & Annuity			Corporate			Consolidated
	Global Insurance			U.S. Insurance			Reinsurance			Alterra at Lloyd’s			Latin America			Total			Reinsurance
Gross premiums written	$	70,271		$	71,871		$	105,292		$	45,922		$	30,524		$	323,880		$	1,333		$	—		$	325,213
Reinsurance premiums ceded		(34,075	)		(21,513	)		(2,395	)		(2,397	)		(129	)		(60,509	)		(102	)		—			(60,611	)
Net premiums written	$	36,196		$	50,358		$	102,897		$	43,525		$	30,395		$	263,371		$	1,231		$	—		$	264,602
Earned premiums	$	96,777		$	79,200		$	210,320		$	42,612		$	6,002		$	434,911		$	1,333		$	—		$	436,244
Earned premiums ceded		(41,097	)		(27,770	)		(15,522	)		(9,310	)		(11	)		(93,710	)		(102	)		—			(93,812	)
Net premiums earned		55,680			51,430			194,798			33,302			5,991			341,201			1,231			—			342,432
Net losses and loss expenses		(23,775	)		(32,199	)		(115,992	)		(15,254	)		(3,792	)		(191,012	)		—			—			(191,012	)
Claims and policy benefits		—			—			—			—			—			—			(15,060	)		—			(15,060	)
Acquisition costs		(1,265	)		(6,880	)		(44,186	)		(6,658	)		(1,699	)		(60,688	)		(171	)		—			(60,859	)
General and administrative expenses		(6,435	)		(9,975	)		(16,866	)		(6,275	)		(2,245	)		(41,796	)		(577	)		—			(42,373	)
Other income (loss)		771			337			61			177			—			1,346			(43	)		—			1,303
Underwriting income (loss)		24,976			2,713			17,815			5,292			(1,745	)		49,051			n/a			—			n/a
Net investment income																				12,182			47,529			59,711
Net realized and unrealized gains on investments																				3,321			12,090			15,411
Net impairment losses recognized in earnings																							(151	)		(151	)
Corporate other income																							24			24
Interest expense																							(7,551	)		(7,551	)
Net foreign exchange losses																							(3,353	)		(3,353	)
Merger and acquisition expenses																							(550	)		(550	)
Corporate general and administrative expenses																							(14,277	)		(14,277	)
Income before taxes																			$	883		$	33,761		$	83,695
Loss ratio		42.7	%		62.6	%		59.5	%		45.8	%		63.3	%		56.0	%
Acquisition cost ratio		2.3	%		13.4	%		22.7	%		20.0	%		28.4	%		17.8	%
General and administrative expense ratio		11.6	%		19.4	%		8.7	%		18.8	%		37.5	%		12.2	%
Combined ratio		56.5	%		95.4	%		90.9	%		84.6	%		129.1	%		86.0	%

ALTERRA CAPITAL HOLDINGS LIMITED

SCHEDULE OF SUPPLEMENTAL UNDERWRITING DATA–QUARTER ENDED DECEMBER 31, 2010 (Unaudited) – RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

	Property and Casualty																		Life & Annuity			Corporate			Consolidated
	Global Insurance			U.S. Insurance			Reinsurance			Alterra at Lloyd’s			Latin America			Total			Reinsurance
Gross premiums written	$	101,116		$	77,745		$	109,365		$	20,427		$	4,808		$	313,461		$	1,937		$	—		$	315,398
Reinsurance premiums ceded		(51,700	)		(20,984	)		(2,897	)		(1,859	)		(11	)		(77,451	)		(166	)		—			(77,617	)
Net premiums written	$	49,416		$	56,761		$	106,468		$	18,568		$	4,797		$	236,010		$	1,771		$	—		$	237,781
Earned premiums	$	98,024		$	82,828		$	211,804		$	44,381		$	6,709		$	443,746		$	1,937		$	—		$	445,683
Earned premiums ceded		(41,104	)		(28,883	)		(21,062	)		(11,894	)		(20	)		(102,963	)		(166	)		—			(103,129	)
Net premiums earned		56,920			53,945			190,742			32,487			6,689			340,783			1,771			—			342,554
Net losses and loss expenses		(31,842	)		(35,723	)		(95,732	)		(11,356	)		(4,394	)		(179,047	)		—			—			(179,047	)
Claims and policy benefits		—			—			—			—			—			—			(18,551	)		—			(18,551	)
Acquisition costs		(1,628	)		(8,755	)		(37,487	)		(3,963	)		(1,809	)		(53,642	)		79			—			(53,563	)
General and administrative expenses		(9,782	)		(9,582	)		(24,057	)		(10,260	)		(2,583	)		(56,264	)		(1,088	)		—			(57,352	)
Other income (loss)		—			68			(216	)		2,006			—			1,858			357			—			2,215
Underwriting income (loss)		13,668			(47	)		33,250			8,914			(2,097	)		53,688			n/a			—			n/a
Net investment income																				12,084			48,996			61,080
Net realized and unrealized gains on investments																				3,981			5,844			9,825
Net impairment losses recognized in earnings																							(1,774	)		(1,774	)
Corporate other income																							647			647
Interest expense																							(7,866	)		(7,866	)
Net foreign exchange gains																							382			382
Merger and acquisition expenses																							(500	)		(500	)
Corporate general and administrative expenses																							(19,407	)		(19,407	)
(Loss) income before taxes																			$	(1,367	)	$	26,322		$	78,643
Loss ratio		55.9	%		66.2	%		50.2	%		35.0	%		65.7	%		52.5	%
Acquisition cost ratio		2.9	%		16.2	%		19.7	%		12.2	%		27.0	%		15.7	%
General and administrative expense ratio		17.2	%		17.8	%		12.6	%		31.6	%		38.6	%		16.5	%
Combined ratio		76.0	%		100.2	%		82.5	%		78.7	%		131.3	%		84.8	%

ALTERRA CAPITAL HOLDINGS LIMITED

GLOBAL INSURANCE SEGMENT DATA (Unaudited) – RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

	FOR THE QUARTERS ENDED
	Dec. 31, 2011			Sept. 30, 2011			June 30, 2011			Mar. 31, 2011			Dec. 31, 2010			Sept. 30, 2010			June 30, 2010			Mar. 31, 2010
Gross premiums written	$	97,660		$	73,297		$	130,909		$	63,895		$	101,116		$	70,271		$	132,312		$	66,421
Reinsurance premiums ceded		(50,172	)		(37,625	)		(55,133	)		(38,524	)		(51,700	)		(34,075	)		(46,257	)		(38,576	)
Net premiums written	$	47,488		$	35,672		$	75,776		$	25,371		$	49,416		$	36,196		$	86,055		$	27,845
Earned premiums	$	91,077		$	93,467		$	88,892		$	90,651		$	98,024		$	96,777		$	99,874		$	97,041
Earned premiums ceded		(42,827	)		(48,456	)		(43,286	)		(40,779	)		(41,104	)		(41,097	)		(43,676	)		(47,246	)
Net premiums earned		48,250			45,011			45,606			49,872			56,920			55,680			56,198			49,795
Net losses and loss expenses		(15,152	)		(21,288	)		(23,689	)		(31,624	)		(31,842	)		(23,775	)		(35,927	)		(37,279	)
Acquisition costs		(1,084	)		748			1,117			(264	)		(1,628	)		(1,265	)		(797	)		309
General and administrative expenses		(6,952	)		(6,699	)		(6,774	)		(7,952	)		(9,782	)		(6,435	)		(6,501	)		(5,897	)
Other income (loss)		(128	)		—			85			729			—			771			—			(11	)
Underwriting income	$	24,934		$	17,772		$	16,345		$	10,761		$	13,668		$	24,976		$	12,973		$	6,917
Loss ratio		31.4	%		47.3	%		51.9	%		63.4	%		55.9	%		42.7	%		63.9	%		74.9	%
Acquisition cost ratio		2.2	%		(1.7	%)		(2.4	%)		0.5	%		2.9	%		2.3	%		1.4	%		(0.6	%)
General and administrative expense ratio		14.4	%		14.9	%		14.9	%		15.9	%		17.2	%		11.6	%		11.6	%		11.8	%
Combined ratio		48.1	%		60.5	%		64.3	%		79.9	%		76.0	%		56.5	%		76.9	%		86.1	%

ALTERRA CAPITAL HOLDINGS LIMITED

U.S. INSURANCE SEGMENT DATA (Unaudited) – RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

	FOR THE QUARTERS ENDED
	Dec. 31, 2011			Sept. 30, 2011			June 30, 2011			Mar. 31, 2011			Dec. 31, 2010			Sept. 30, 2010			June 30, 2010			Mar. 31, 2010
Gross premiums written	$	102,279		$	84,858		$	109,794		$	77,765		$	77,745		$	71,871		$	97,487		$	76,887
Reinsurance premiums ceded		(45,443	)		(30,579	)		(28,227	)		(38,317	)		(20,984	)		(21,513	)		(6,852	)		(49,227	)
Net premiums written	$	56,836		$	54,279		$	81,567		$	39,448		$	56,761		$	50,358		$	90,635		$	27,660
Earned premiums	$	90,048		$	83,279		$	82,244		$	81,470		$	82,828		$	79,200		$	76,032		$	73,890
Earned premiums ceded		(34,078	)		(28,004	)		(23,835	)		(27,801	)		(28,883	)		(27,770	)		(28,588	)		(39,977	)
Net premiums earned		55,970			55,275			58,409			53,669			53,945			51,430			47,444			33,913
Net losses and loss expenses		(45,129	)		(36,002	)		(38,012	)		(34,415	)		(35,723	)		(32,199	)		(29,052	)		(21,363	)
Acquisition costs		(8,349	)		(9,669	)		(10,400	)		(7,986	)		(8,755	)		(6,880	)		(9,135	)		(3,674	)
General and administrative expenses		(12,299	)		(10,228	)		(11,374	)		(11,270	)		(9,582	)		(9,975	)		(7,986	)		(8,472	)
Other income (loss)		84			58			54			83			68			337			97			5
Underwriting (loss) income	$	(9,723	)	$	(566	)	$	(1,323	)	$	81		$	(47	)	$	2,713		$	1,368		$	409
Loss ratio		80.6	%		65.1	%		65.1	%		64.1	%		66.2	%		62.6	%		61.2	%		63.0	%
Acquisition cost ratio		14.9	%		17.5	%		17.8	%		14.9	%		16.2	%		13.4	%		19.3	%		10.8	%
General and administrative expense ratio		22.0	%		18.5	%		19.5	%		21.0	%		17.8	%		19.4	%		16.8	%		25.0	%
Combined ratio		117.5	%		101.1	%		102.4	%		100.0	%		100.2	%		95.4	%		97.3	%		98.8	%

ALTERRA CAPITAL HOLDINGS LIMITED

REINSURANCE SEGMENT DATA (Unaudited) - RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

	FOR THE QUARTERS ENDED
	Dec. 31, 2011			Sept. 30, 2011			June 30, 2011			Mar. 31, 2011			Dec. 31, 2010			Sept. 30, 2010			June 30, 2010			Mar. 31, 2010
Gross premiums written	$	88,397		$	121,329		$	244,899		$	360,727		$	109,365		$	105,292		$	117,614		$	154,829
Reinsurance premiums ceded		(1,670	)		(11,055	)		(27,675	)		(35,252	)		(2,897	)		(2,395	)		(13,348	)		(45,351	)
Net premiums written	$	86,727		$	110,274		$	217,224		$	325,475		$	106,468		$	102,897		$	104,266		$	109,478
Earned premiums	$	207,129		$	206,698		$	203,470		$	244,340		$	211,804		$	210,320		$	174,442		$	95,737
Earned premiums ceded		(17,718	)		(17,146	)		(11,815	)		(19,901	)		(21,062	)		(15,522	)		(19,054	)		(15,958	)
Net premiums earned		189,411			189,552			191,655			224,439			190,742			194,798			155,388			79,779
Net losses and loss expenses		(97,328	)		(108,135	)		(122,576	)		(183,908	)		(95,732	)		(115,992	)		(82,278	)		(50,061	)
Acquisition costs		(42,026	)		(41,781	)		(42,947	)		(47,760	)		(37,487	)		(44,186	)		(32,604	)		(14,965	)
General and administrative expenses		(14,585	)		(16,470	)		(21,647	)		(22,272	)		(24,057	)		(16,866	)		(13,975	)		(7,832	)
Other income (loss)		(100	)		777			548			—			(216	)		61			155			—
Underwriting income (loss)	$	35,372		$	23,943		$	5,033		$	(29,501	)	$	33,250		$	17,815		$	26,686		$	6,921
Loss ratio		51.4	%		57.0	%		64.0	%		81.9	%		50.2	%		59.5	%		53.0	%		62.7	%
Acquisition cost ratio		22.2	%		22.0	%		22.4	%		21.3	%		19.7	%		22.7	%		21.0	%		18.8	%
General and administrative expense ratio		7.7	%		8.7	%		11.3	%		9.9	%		12.6	%		8.7	%		9.0	%		9.8	%
Combined ratio		81.3	%		87.8	%		97.7	%		113.1	%		82.5	%		90.9	%		82.9	%		91.3	%

ALTERRA CAPITAL HOLDINGS LIMITED

ALTERRA AT LLOYD’S SEGMENT DATA (Unaudited) - RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

	FOR THE QUARTERS ENDED
	Dec. 31, 2011			Sept. 30, 2011			June 30, 2011			Mar. 31, 2011			Dec. 31, 2010			Sept. 30, 2010			June 30, 2010			Mar. 31, 2010
Gross premiums written	$	27,933		$	44,816		$	72,428		$	107,890		$	20,427		$	45,922		$	41,308		$	72,117
Reinsurance premiums ceded		(8,888	)		(6,723	)		(24,918	)		(23,179	)		(1,859	)		(2,397	)		(13,233	)		(19,959	)
Net premiums written	$	19,045		$	38,093		$	47,510		$	84,711		$	18,568		$	43,525		$	28,075		$	52,158
Earned premiums	$	52,850		$	50,534		$	58,117		$	63,164		$	44,381		$	42,612		$	40,195		$	37,460
Earned premiums ceded		(14,952	)		(10,850	)		(14,540	)		(20,580	)		(11,894	)		(9,310	)		(7,120	)		(7,469	)
Net premiums earned		37,898			39,684			43,577			42,584			32,487			33,302			33,075			29,991
Net losses and loss expenses		(64,346	)		(24,462	)		(21,072	)		(48,443	)		(11,356	)		(15,254	)		(12,322	)		(16,258	)
Acquisition costs		(7,977	)		(6,230	)		(9,946	)		(12,652	)		(3,963	)		(6,658	)		(6,059	)		(5,767	)
General and administrative expenses		(7,271	)		(8,007	)		(7,773	)		(8,253	)		(10,260	)		(6,275	)		(4,717	)		(2,713	)
Other income (loss)		851			(27	)		165			215			2,006			177			173			178
Underwriting (loss) income	$	(40,845	)	$	958		$	4,951		$	(26,549	)	$	8,914		$	5,292		$	10,150		$	5,431
Loss ratio		169.8	%		61.6	%		48.4	%		113.8	%		35.0	%		45.8	%		37.3	%		54.2	%
Acquisition cost ratio		21.0	%		15.7	%		22.8	%		29.7	%		12.2	%		20.0	%		18.3	%		19.2	%
General and administrative expense ratio		19.2	%		20.2	%		17.8	%		19.4	%		31.6	%		18.8	%		14.3	%		9.0	%
Combined ratio		210.0	%		97.5	%		89.0	%		162.8	%		78.7	%		84.6	%		69.8	%		82.5	%

ALTERRA CAPITAL HOLDINGS LIMITED

LATIN AMERICA SEGMENT DATA (Unaudited)

(Expressed in thousands of U.S. Dollars)

	FOR THE QUARTERS ENDED
	Dec. 31, 2011			Sept. 30, 2011			June 30, 2011			Mar. 31, 2011			Dec. 31, 2010			Sept. 30, 2010			June 30, 2010			Mar. 31, 2010
Gross premiums written	$	8,545		$	61,206		$	4,947		$	17,136		$	4,808		$	30,524		$	9,458		$	22
Reinsurance premiums ceded		(876	)		(4,819	)		(572	)		(2,065	)		(11	)		(129	)		—			—
Net premiums written	$	7,669		$	56,387		$	4,375		$	15,071		$	4,797		$	30,395		$	9,458		$	22
Earned premiums	$	18,363		$	18,131		$	9,355		$	9,202		$	6,709		$	6,002		$	378		$	6
Earned premiums ceded		(1,803	)		(1,343	)		(490	)		(294	)		(20	)		(11	)		—			—
Net premiums earned		16,560			16,788			8,865			8,908			6,689			5,991			378			6
Net losses and loss expenses		(9,578	)		(8,634	)		(5,784	)		(6,016	)		(4,394	)		(3,792	)		(238	)		(4	)
Acquisition costs		(4,813	)		(4,357	)		(2,382	)		(1,787	)		(1,809	)		(1,699	)		(80	)		(1	)
General and administrative expenses		(2,105	)		(2,431	)		(3,053	)		(2,456	)		(2,583	)		(2,245	)		(1,954	)		(1,127	)
Underwriting income (loss)	$	64		$	1,366		$	(2,354	)	$	(1,351	)	$	(2,097	)	$	(1,745	)	$	(1,894	)	$	(1,126	)
Loss ratio		57.8	%		51.4	%		65.2	%		67.5	%		65.7	%		63.3	%		62.9	%		66.7	%
Acquisition cost ratio		29.1	%		26.0	%		26.9	%		20.1	%		27.0	%		28.4	%		21.2	%		16.7	%
General and administrative expense ratio		12.7	%		14.5	%		34.4	%		27.6	%		38.6	%		37.5	%		n/m			n/m
Combined ratio		99.6	%		91.9	%		126.6	%		115.2	%		131.3	%		129.1	%		n/m			n/m

ALTERRA CAPITAL HOLDINGS LIMITED

SEGMENT GROSS PREMIUMS WRITTEN BY LINE OF BUSINESS (Unaudited) - RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

		FOR THE QUARTERS ENDED											YEAR ENDED
		Dec. 31, 2011			Sept. 30, 2011			June 30, 2011			Mar. 31, 2011		Dec. 31, 2011
Property & Casualty:
Global Insurance:
Aviation	S	$	20,410		$	6,736		$	3,814		$	1,416	$	32,376
Excess Liability	L		21,281			20,365			34,659			22,277		98,582
Professional Liability	L		40,360			30,590			62,402			24,529		157,881
Property	S		15,609			15,606			30,034			15,673		76,922
			97,660			73,297			130,909			63,895		365,761
U.S. Insurance:
General Liability	L		31,618			24,925			25,118			22,993		104,654
Marine	S		23,806			22,189			25,389			17,109		88,493
Professional Liability	L		15,720			13,318			8,509			6,622		44,169
Property	S		31,135			24,426			50,778			31,041		137,380
			102,279			84,858			109,794			77,765		374,696
Reinsurance:
Agriculture	S		186			998			8,713			20,785		30,682
Auto	S		20,548			7,716			55,072			15,024		98,360
Aviation	S		337			14,440			80			904		15,761
Credit/ Surety	S		1,801			98			571			22,707		25,177
General Casualty	L		12,951			20,923			22,045			15,427		71,346
Marine & Energy	S		2,918			1,647			(678	)		16,549		20,436
Medical Malpractice	L		1,673			6,867			11,223			17,582		37,345
Other	S		(181	)		1,112			447			1,693		3,071
Professional Liability	L		20,270			39,877			39,462			59,684		159,293
Property	S		18,731			22,115			103,390			138,866		283,102
Whole Account	S/L		2,408			(1,946	)		268			35,070		35,800
Workers’ Compensation	L		6,755			7,482			4,306			16,436		34,979
			88,397			121,329			244,899			360,727		815,352
Alterra at Lloyd’s:
Accident & Health	S		5,646			9,523			8,380			13,544		37,093
Aviation	S		5,562			4,130			1,810			1,767		13,269
Financial Institutions	L		8,137			3,591			6,441			9,036		27,205
International Casualty	L		1,947			7,903			8,263			33,789		51,902
Marine	S		1,493			—			—			—		1,493
Professional Liability	L		1,868			440			10,466			7,922		20,696
Property	S		3,280			19,229			37,068			41,832		101,409
			27,933			44,816			72,428			107,890		253,067
Latin America:
Aviation	S		—			230			—			—		230
General Liability	L		179			1,947			223			957		3,306
Marine	S		489			2,484			59			544		3,576
Property	S		2,914			48,159			3,681			13,935		68,689
Surety	S		4,963			8,386			984			1,700		16,033
			8,545			61,206			4,947			17,136		91,834
Aggregate Property & Casualty		$	324,814		$	385,506		$	562,977		$	627,413	$	1,900,710
Life & Annuity
Annuity		$	770		$	449		$	271		$	336	$	1,826
Life			399			373			659			99		1,530
Aggregate Life & Annuity		$	1,169		$	822		$	930		$	435	$	3,356
		$	325,983		$	386,328		$	563,907		$	627,848	$	1,904,066
S = Short tail lines		$	160,851		$	208,251		$	329,726		$	372,624	$	1,071,452
L = Long tail lines			163,963			177,255			233,251			254,789		829,258
Aggregate Property & Casualty		$	324,814		$	385,506		$	562,977		$	627,413	$	1,900,710

ALTERRA CAPITAL HOLDINGS LIMITED

SEGMENT GROSS PREMIUMS WRITTEN BY LINE OF BUSINESS (Unaudited) - RE-PRESENTED

(Expressed in thousands of U.S. Dollars)

		FOR THE QUARTERS ENDED											YEAR ENDED
		Dec. 31, 2010			Sept. 30, 2010			June 30, 2010			Mar. 31, 2010		Dec. 31, 2010
Property & Casualty:
Global Insurance
Aviation	S	$	22,677		$	8,247		$	6,615		$	2,349	$	39,888
Excess Liability	L		18,703			14,384			33,198			23,648		89,933
Professional Liability	L		47,737			36,673			65,216			27,573		177,199
Property	S		11,999			10,967			27,283			12,851		63,100
			101,116			70,271			132,312			66,421		370,120
U.S. Insurance:
General Liability	L		28,572			25,566			27,625			23,014		104,777
Marine	S		17,758			15,637			17,996			16,063		67,454
Professional Liability	L		2,928			3,613			3,667			2,246		12,454
Property	S		28,487			27,055			48,199			35,564		139,305
			77,745			71,871			97,487			76,887		323,990
Reinsurance:
Agriculture	S		(1,406	)		(2,665	)		(2,513	)		35,806		29,222
Auto	S		22,578			9,702			5			—		32,285
Aviation	S		2,596			15,232			8,561			4,822		31,211
Credit/ Surety	S		671			195			(1,891	)		—		(1,025	)
General Casualty	L		17,463			18,330			(857	)		13,051		47,987
Marine & Energy	S		(1,549	)		7,101			4,894			4,100		14,546
Medical Malpractice	L		19,554			(3,131	)		7,813			27,155		51,391
Other	S		520			1,128			92			989		2,729
Professional Liability	L		28,538			37,926			32,005			11,919		110,388
Property	S		5,827			22,266			59,665			45,911		133,669
Whole Account	S/L		289			(1,353	)		2,362			2,573		3,871
Workers’ Compensation	L		14,284			561			7,478			8,503		30,826
			109,365			105,292			117,614			154,829		487,100
Alterra at Lloyd’s:
Accident & Health	S		5,570			5,919			6,022			13,410		30,921
Aviation	S		5,224			3,946			2,565			4,403		16,138
Financial Institutions	L		384			8,130			4,846			6,088		19,448
International Casualty	L		1,930			3,702			6,173			13,684		25,489
Professional Liability	L		4,204			4,330			4,161			6,896		19,591
Property	S		3,115			19,895			17,541			27,636		68,187
			20,427			45,922			41,308			72,117		179,774
Latin America:
Aviation	S		—			81			—			—		81
General Liability	L		615			1,783			9			—		2,407
Marine	S		—			1,725			110			—		1,835
Property	S		3,307			20,192			8,939			22		32,460
Surety	S		886			6,743			400			—		8,029
			4,808			30,524			9,458			22		44,812
Aggregate Property & Casualty		$	313,461		$	323,880		$	398,179		$	370,276	$	1,405,796
Life & Annuity:
Annuity		$	1,129		$	—		$	6		$	—	$	1,135
Life			808			1,333			796			863		3,800
Aggregate Life & Annuity		$	1,937		$	1,333		$	802		$	863	$	4,935
		$	315,398		$	325,213		$	398,981		$	371,139	$	1,410,731
S = Short tail lines		$	128,404		$	172,689		$	205,664		$	205,212	$	711,970
L = Long tail lines			185,057			151,191			192,515			165,064		693,826
Aggregate Property & Casualty		$	313,461		$	323,880		$	398,179		$	370,276	$	1,405,796