[LETTERHEAD OF WILLKIE FARR & GALLAGHER LLP]



VIA EDGAR
- ---------


April 7, 2006


Securities and Exchange Commission
100 F Street, N.E.
Judiciary Plaza
Washington, D.C.  20549
Attn:  Jim B. Rosenberg, Senior Assistant Chief Accountant
       Division of Corporation Finance


Re:  W. R. Berkley Corporation
     Form 10-K for the Fiscal Year Ended December 31, 2005
     Filed March 13, 2006
     File No. 1-15202
     -----------------------------------------------------

Dear Mr. Rosenberg:

     On behalf of W. R. Berkley Corporation ("Berkley" or the "Company"), set
forth below are Berkley's responses to the comments of the staff (the "Staff")
of the Securities and Exchange Commission (the "Commission") contained in the
letter dated March 23, 2006 from Jim B. Rosenberg to Eugene G. Ballard,
Berkley's Senior Vice President, Chief Financial Officer and Treasurer. For your
convenience, we have set forth below the Staff's comments in italics, followed
by Berkley's responses thereto. Berkley proposes to make these changes described
below commencing with its Quarterly Report on Form 10-Q for the Quarterly Period
Ended March 31, 2006.

Form 10-K for the Fiscal Year Ended December 31, 2005 (the "2005 Form 10-K")

Management's Discussion and Analysis of Financial Condition and Results of
Operations

Reserves for Losses and Loss Expenses, page 3

1.   You disclose that in circumstances where one actuarial method is considered
     more credible than the others, you use that method to establish a point
     estimate. Please provide us, in disclosure-type format, expanded disclosure
     that discusses the circumstances in which specific actuarial techniques
     would be considered more credible. In addition, when multiple point
     estimates are used, include the range of these point estimates.




Mr. Jim B. Rosenberg
Securities and Exchange Commission
April 7, 2006
Page 2

     Berkley will add the following disclosure to describe the circumstances in
     which specific actuarial techniques are considered by Berkley to be more
     credible than others (following the sentence, "In circumstances where one
     actuarial method is considered more credible than the others, that method
     is used to set the point estimate."):

          For example, the paid loss and incurred loss development methods rely
          on historical paid and incurred loss data. For new lines of business,
          where there is insufficient history of paid and incurred claims data,
          or in circumstances where there have been significant changes in claim
          practices, the paid and incurred loss development methods would be
          less credible than other actuarial methods.

     As described in its 2005 Form 10-K, in establishing its loss reserves,
     Berkley analyzes its actuarial data and reserves by line of business,
     coverage and accident or policy year, as appropriate, for each of its
     operating units. For each of those analyses, a single actuarial point
     estimate is selected after considering a variety of actuarial techniques
     and projections. Berkley does not calculate a reserve range around the
     point estimate.

2.   Please provide us, in disclosure-type format, the following expanded
     disclosure for your reserve sensitivity analysis:

     o    Provide this analysis on a disaggregated basis by line of business.

     o    Discuss the link between the frequency and severity loss activity
          measures and the key assumptions you identified that affect the loss
          reserve best estimate.

     o    Tell us whatever or not these changes in measures are reasonably
          likely. If the changes are not reasonably likely, please provide us a
          revised analysis that discloses the reasonably likely changes and the
          effect that these changes would have on your reported results,
          financial position and liquidity.

     We do not believe it would be useful to investors to present this reserve
     sensitivity analysis by line of business since the relative impact of
     changes in loss frequency and severity would be the same, whether applied
     in the aggregate or for each such line of business.

     In order to clarify the relationship between frequency and severity
     measures and the key assumptions affecting loss reserve estimates, Berkley
     will add the following disclosure as well as an expanded loss sensitivity
     table:




Mr. Jim B. Rosenberg
Securities and Exchange Commission
April 7, 2006
Page 3


          Loss frequency and severity are measures of loss activity that are
          considered in determining the key assumptions described in our
          discussion of loss and loss expense reserves, including expected loss
          ratios, rate of loss cost inflation and reported and paid loss
          emergence patterns. Loss frequency is a measure of the number of
          claims per unit of insured exposure, and loss severity is a measure of
          the average size of claims. Factors affecting loss frequency include
          the effectiveness of loss controls and safety programs and changes in
          economic activity or weather patterns. Factors affecting loss severity
          include changes in policy limits, retentions, rate of inflation and
          judicial interpretations. If the actual level of loss frequency and
          severity are higher or lower than expected, the ultimate losses will
          be different than management's estimate. The following table reflects
          the impact of changes (which could be favorable or unfavorable) in
          frequency and severity on our loss estimate of $2,531,655 for claims
          occurring in 2005 (dollars in thousands):

                                                   Frequency (+/-)
               Severity (+/-)              1%           5%               10%
               --------------              --           --               ---
                   1%                  $ 50,866      $153,165          $281,014
                   5%                   153,165       259,495           392,407
                  10%                   281,014       392,407           531,648

     The Company believes that the outcomes presented in the above table
     represent reasonably likely fluctuations in its loss estimates.

Liquidity and Capital Resources, page 14

3.   We note on page 11 that your investment strategy is to maintain an
     appropriate relationship between the average duration of the investment
     portfolio and the approximate duration of liabilities. Please provide us in
     disclosure-type format, a more robust discussion of the reasonably likely
     impact the payment of claims will have on known trends and uncertainties,
     in particular cash outflows from operations. In the disclosure please
     include a discussion of your asset/liability management process and whether
     there are any significant variations between the maturity of your
     investments and the expected payment of your loss reserves. Include a
     discussion of the impact of selling securities before anticipated or the
     use of credit facilities to pay for policy liabilities will have on your
     future liquidity and results of operations.




Mr. Jim B. Rosenberg
Securities and Exchange Commission
April 7, 2006
Page 4


     In order to further clarify the reference to average duration of the
     investment portfolio and to expand upon the funding for claim payments,
     Berkley will revise its discussion of the impact of the payment of claims
     on its liquidity contained under "Liquidity and Capital Resources" as
     follows:

          The Company's insurance subsidiaries' principal sources of cash are
          premiums, investment income, service fees and proceeds from sales and
          maturities of portfolio investments. The principal uses of cash are
          payments for claims, taxes, operating expenses and dividends. As of
          December 31, 2005, the insurance subsidiaries' undiscounted reserves
          for loss and loss expenses were $7.4 billion. The Company estimates
          that approximately $1.6 billion of those reserves will be paid in 2006
          and that approximately $3.5 billion will be paid from 2007 through
          2010.

          The Company expects its insurance subsidiaries to fund the payment of
          losses with cash received from premiums, investment income and fees.
          The Company targets an average duration for its investment portfolio
          that is within one year of the average duration of its liabilities so
          that portions of its investment portfolio mature throughout the claim
          cycle and are available for the payment of claims if necessary. In the
          event operating cash flow and proceeds from maturities and prepayments
          of fixed income securities are not sufficient to fund claim payments
          and other cash requirements, the remainder of the Company's cash and
          investments is available to pay claims and other obligations as they
          become due. The Company's investment portfolio is highly liquid, with
          approximately 88% invested in cash, cash equivalents and marketable
          fixed income securities as of December 31, 2005. If the sale of fixed
          income securities were to become necessary, a realized gain or loss
          equal to the difference between the cost and sales price of securities
          sold would be recognized.

     As the Company does not have a credit facility available for claim
     payments, we do not propose to include additional disclosure regarding the
     use of credit facilities.

     The Company will conform its disclosure regarding the targeted duration of
     its investment portfolio contained under "Investments" to the above revised
     description.




Mr. Jim B. Rosenberg
Securities and Exchange Commission
April 7, 2006
Page 5


     Pursuant to your letter, on behalf of Berkley, we hereby acknowledge that:

     o    Berkley is responsible for the adequacy and accuracy of the disclosure
          in its 2005 Form 10-K;

     o    Staff comments or changes to disclosure in response to Staff comments
          do not foreclose the Commission from taking any action with respect to
          Berkley's 2005 Form 10-K; and

     o    Berkley may not assert Staff comments as a defense in any proceeding
          initiated by the Commission or any person under the Federal securities
          laws of the United States.

     Should any member of the Staff have any questions or comments concerning
this letter, please do not hesitate to call me at (212) 728-8592.

Very truly yours,

/s/ Jeffrey S. Hochman

Jeffrey S. Hochman

Enclosures

cc:  Lisa K. Vanjoske
     Dana Hartz
     Eugene G. Ballard
     Ira S. Lederman, Esq.