Exhibit 99.1

W. R. Berkley Corporation 475 Steamboat Road Greenwich, Connecticut 06830 (203) 629-3000		NEWS RELEASE

FOR IMMEDIATE RELEASE		CONTACT:		Karen A. Horvath Vice President — External Financial Communications (203) 629-3000

W. R. BERKLEY CORPORATION REPORTS FIRST QUARTER RESULTS
Net Income per Share up 7%

     Greenwich, CT, April 25, 2011 — W. R. Berkley Corporation (NYSE: WRB) today reported net income for the first quarter of 2011 of $116 million, or 79 cents per share, compared with $119 million, or 74 cents per share, for the first quarter of 2010.

Summary Financial Data
(Amounts in thousands, except per share data)

		First Quarter
		2011				2010
Gross premiums written		$	1,269,858			$	1,126,120
Net premiums written			1,083,303				983,950
Net income			116,487				118,610
Net income per diluted share			0.79				0.74
Operating income (1)			97,697				114,767
Operating income per diluted share			0.66				0.72

W. R. Berkley Corporation		Page 2

First quarter highlights included:

	•		Net premiums written increased 10%.
	•		GAAP combined ratio was 96.3%.
	•		Return on equity was 12.6%.
	•		Book value per share was $26.78.

     Commenting on the Company’s performance, William R. Berkley, chairman and chief executive officer, said: “We are pleased with our first quarter results. Prices for the quarter were up in nearly all areas, with an average increase of almost one percent. This is the first time in seventeen quarters that we can make such a positive statement. Our growth in the quarter came mainly from our international segment and select specialty markets. Our renewal retention rate is approximately 80%, approaching our historical levels. There are increasing signs of a turn in the cycle, but as always, the change starts gradually.

     “Recent events as well as revisions to catastrophe modeling tools are changing the way people view catastrophe exposures. We are beginning to see material rate increases not just limited to catastrophe business, but also in a number of other lines of business. The Company has selectively increased the non-casualty component of our business mix, although we remain cognizant of the volatility element in certain lines. We are also particularly pleased with the expansion of our non-US business.

     “We continue to maintain an investment portfolio with an overwhelmingly high-quality, fixed income focus but, given the current interest rate environment, we are also searching for appropriate alternatives for new funds. We continue to refine our investment strategies and have a greater focus on total return investment opportunities that include capital gains,” Mr. Berkley concluded.

W. R. Berkley Corporation		Page 3

Webcast Conference Call

     The Company will hold its quarterly conference call with analysts and investors to discuss its earnings and other information on Tuesday, April 26, 2011 at 9:00 a.m. eastern time. The conference call will be webcast live on the Company’s website at www.wrberkley.com. A recording of the call will be available on the Company’s website approximately two hours after the end of the conference call.

About W. R. Berkley Corporation

     Founded in 1967, W. R. Berkley Corporation is an insurance holding company that is among the largest commercial lines writers in the United States and operates in five segments of the property casualty insurance business: specialty insurance, regional property casualty insurance, alternative markets, reinsurance and international.

Forward Looking Information

This is a “Safe Harbor” Statement under the Private Securities Litigation Reform Act of 1995. Any forward-looking statements contained herein, including statements related to our outlook for the industry and for our performance for the year 2011 and beyond, are based upon the Company’s historical performance and on current plans, estimates and expectations. The inclusion of this forward-looking information should not be regarded as a representation by us or any other person that the future plans, estimates or expectations contemplated by us will be achieved. They are subject to various risks and uncertainties, including but not limited to: the cyclical nature of the property casualty industry; the long-tail and potentially volatile nature of the insurance and reinsurance business; product demand and pricing; claims development and the process of estimating reserves; investment risks, including those of our portfolio of fixed maturity securities and investments in equity securities, including investments in financial institutions, municipal bonds, mortgage-backed securities, loans receivable, investment funds, merger arbitrage and private equity investments; the impact of significant competition; the potential impact of the economic downturn, and any legislative, regulatory, accounting or other initiatives taken in response to it, on our results and financial condition; the uncertain nature of damage theories and loss amounts; natural and man-made catastrophic losses, including as a result of terrorist activities; the success of our new ventures or acquisitions and the availability of other opportunities; the availability of reinsurance; our retention under the Terrorism Risk Insurance Programs Reauthorization Act of 2007; the ability of our reinsurers to pay reinsurance recoverables owed to us; foreign currency and political risks relating to our international operations; other legislative and regulatory developments, including those related to business practices in the insurance industry; changes in the ratings assigned to us or our insurance company subsidiaries by rating agencies; the availability of dividends from our insurance company subsidiaries; our ability to attract and retain qualified employees; and other risks detailed from time to time in the Company’s filings with the Securities and Exchange Commission. These risks and uncertainties could cause our actual results for the year 2011 and beyond to differ materially from those expressed in any forward-looking statement we make. Any projections of growth in our net premiums written and management fees would not necessarily result in commensurate levels of underwriting and operating profits. Forward-looking statements speak only as of the date on which they are made, and the Company undertakes no obligation to update publicly or revise any forward-looking statement, whether as a result of new information, future developments or otherwise.

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W. R. Berkley Corporation		Page 4

Consolidated Financial Summary
(Amounts in thousands, except per share data)

		First Quarter
		2011				2010
Revenues:
Net premiums written		$	1,083,303			$	983,950
Change in unearned premiums			(100,806	)			(53,389	)
Net premiums earned			982,497				930,561
Net investment income			131,619				138,843
Income from investment funds			14,507				4,718
Insurance service fees			22,173				21,485
Net investment gains:
Net realized gains on investment sales			29,284				8,494
Other-than-temporary impairments			—				(2,582	)
Net investment gains			29,284				5,912
Revenues from wholly-owned investees			53,887				51,576
Other income			384				452
Total revenues			1,234,351				1,153,547
Expenses:
Losses and loss expenses			607,095				549,973
Other operating costs and expenses			384,831				367,967
Expenses from wholly-owned investees			53,816				48,974
Interest expense			28,117				26,041
Total expenses			1,073,859				992,955
Income before income taxes			160,492				160,592
Income tax expense			(44,000	)			(41,811	)
Net income before noncontrolling interests			116,492				118,781
Noncontrolling interests			(5	)			(171	)
Net income to common stockholders		$	116,487			$	118,610
Net income per share:
Basic		$	0.83			$	0.77
Diluted		$	0.79			$	0.74
Average shares outstanding:
Basic			141,177				153,445
Diluted			147,425				159,771

W. R. Berkley Corporation		Page 5

Operating Results by Segment
(Amounts in thousands, except ratios (1))

		First Quarter
		2011				2010
Specialty:
Gross premiums written		$	415,730			$	342,932
Net premiums written			358,117				301,928
Premiums earned			330,207				312,953
Pre-tax income			90,369				75,670
Loss ratio			54.2	%			57.9	%
Expense ratio			33.6	%			33.6	%
GAAP combined ratio			87.8	%			91.5	%
Regional:(2)
Gross premiums written		$	298,841			$	302,641
Net premiums written			279,624				272,032
Premiums earned			261,517				263,669
Pre-tax income			24,898				41,964
Loss ratio			62.4	%			57.2	%
Expense ratio			36.1	%			35.5	%
GAAP combined ratio			98.5	%			92.7	%
Alternative Markets:
Gross premiums written		$	254,847			$	241,351
Net premiums written			200,554				210,405
Premiums earned			148,337				154,785
Pre-tax income			41,630				50,985
Loss ratio			72.6	%			64.6	%
Expense ratio			26.1	%			25.5	%
GAAP combined ratio			98.7	%			90.1	%
Reinsurance:(2)
Gross premiums written		$	112,564			$	106,369
Net premiums written			106,354				98,771
Premiums earned			105,478				99,558
Pre-tax income			25,362				34,420
Loss ratio			62.6	%			50.4	%
Expense ratio			39.2	%			43.8	%
GAAP combined ratio			101.8	%			94.2	%
International:(2)
Gross premiums written		$	187,876			$	132,827
Net premiums written			138,654				100,814
Premiums earned			136,958				99,596
Pre-tax income			2,515				373
Loss ratio			66.5	%			67.9	%
Expense ratio			39.1	%			43.6	%
GAAP combined ratio			105.6	%			111.5	%

W. R. Berkley Corporation		Page 6

Operating Results by Segment (Continued)
(Amounts in thousands, except ratios (1))

		First Quarter
		2011				2010
Corporate and Eliminations:
Net investment gains		$	29,284			$	5,912
Interest expense			(28,117	)			(26,041	)
Other revenues and expenses (3)			(25,449	)			(22,691	)
Pre-tax loss			(24,282	)			(42,820	)
Consolidated:
Gross premiums written		$	1,269,858			$	1,126,120
Net premiums written			1,083,303				983,950
Premiums earned			982,497				930,561
Pre-tax income			160,492				160,592
Loss ratio			61.8	%			59.1	%
Expense ratio			34.5	%			35.0	%
GAAP combined ratio			96.3	%			94.1	%

W. R. Berkley Corporation		Page 7

Selected Balance Sheet Information
(Amounts in thousands, except per share data)

		March 31, 2011				December 31, 2010
Net invested assets (1)		$	13,983,378			$	13,918,768
Total assets			17,983,511				17,528,547
Reserves for losses and loss expenses			9,172,680				9,016,549
Senior notes and other debt			1,497,095				1,500,419
Junior subordinated debentures			242,841				242,784
Common stockholders’ equity (2)			3,791,784				3,702,876
Common stock outstanding			141,599				141,010
Common stockholders’ equity per share			26.78				26.26

W. R. Berkley Corporation		Page 8

Supplemental Information
(Amounts in thousands)

		First Quarter
		2011				2010
Reconciliation of operating income to net income:
Operating income (1)		$	97,697			$	114,767
Investment gains, net of tax			18,790				3,843
Net income		$	116,487			$	118,610
Return on equity (2)			12.6	%			13.2	%
Cash flow from operations		$	51,771			$	57,159
Other operating costs and expenses:
Underwriting expenses		$	339,185			$	325,603
Service expenses			17,329				18,544
Net foreign currency (gains) losses			520				(5,027	)
Other costs and expenses			27,797				28,847
Total		$	384,831			$	367,967

W. R. Berkley Corporation		Page 9

Investment Portfolio
March 31, 2011
(Amounts in thousands)

		Carrying				Percent
		Value				of Total
Fixed maturity securities:
United States government and government agencies		$	1,295,559				9.3	%
State and municipal:
Special revenue			2,129,061				15.2	%
Pre-refunded			1,461,295				10.5	%
State general obligation			1,012,535				7.2	%
Local general obligation			427,260				3.1	%
Corporate backed			449,398				3.2	%
Total state and municipal (1)			5,479,549				39.2	%
Mortgage-backed securities:
Agency			1,052,388				7.5	%
Residential — Prime			267,365				1.9	%
Residential — Alt A			54,490				0.4	%
Commercial			57,999				0.4	%
Total mortgage-backed securities			1,432,242				10.2	%
Corporate:
Industrial			1,192,670				8.5	%
Financial			722,808				5.2	%
Utilities			197,053				1.4	%
Asset-backed			273,692				2.0	%
Other			122,702				0.9	%
Total corporate			2,508,925				18.0	%
Foreign government and foreign government agencies			535,343				3.8	%
Total fixed maturity securities (1)			11,251,618				80.5	%
Equity securities available for sale:
Common stocks			315,297				2.3	%
Preferred stocks
Financial			96,981				0.7	%
Real estate			48,604				0.3	%
Utilities			49,248				0.4	%
Total equity securities available for sale			510,130				3.7	%
Cash and cash equivalents (2)			741,012				5.3	%
Arbitrage trading account			488,202				3.5	%
Investment in arbitrage funds			62,541				0.4	%
Investment funds			548,327				3.9	%
Loans receivable			348,773				2.5	%
Real estate			32,775				0.2	%
Net invested assets		$	13,983,378				100.0	%