Sullivan & Worcester LLP                     T 202 775 1200
         1666 K Street, NW                            F 202 293 2275
         Washington, DC 20006www.sandw.com


                                                      December 21, 2006

VIA EDGAR

EDGAR Operations Branch
Division of Investment Management
Securities and Exchange Commission
100 F Street, N.E.
Washington, DC 20549
                           Met Investors Series Trust
                      (BlackRock Large Cap Core Portfolio)
                      -Registration Statement on Form N-14
                                 CIK 0001126087
                              (File No. 333-139004)

Ladies and Gentlemen:

         This letter reflects responses to oral comments of Tony Burak and
Robert Lamont of the staff of the Securities and Exchange Commission (the
"SEC"), which were received on December 14, 2006 and December 19, 2006,
respectively, in connection with the Registration Statement on Form N-14 of Met
Investors Series Trust (the "Trust"), relating to the acquisition of the assets
of BlackRock Large Cap Portfolio ("Large Cap"), a series of Metropolitan Series
Fund, Inc. (the "Fund"), by and in exchange for shares of BlackRock Large-Cap
Core Portfolio ("Large-Cap Core"), a series of the Trust, which was filed
electronically with the SEC via EDGAR on November 30, 2006.

         Set forth below is each comment and the Series Fund's response thereto.

1.   Comment: Include Tandy language in the response letter.

     Response:  The requested language is included at the end of this letter.

2.   Comment:  In  footnote 2 to the Fee and Expense  Table on page 11,  explain
     what "certain other expenses" are excluded from the expense limitation cap.

     Response:  The  requested  disclosure  has been  added to  footnote  2. See
     attached.

3.   Comment:  If there are  differences  in the investment  strategies  between
     BlackRock  Large Cap and BlackRock  Large-Cap  Core,  add a heading to such
     discussion of differences.

     Response:  There are no  differences  in the  investment  strategies of the
     Portfolios.

4.   Comment:  In  footnote 4 to the Fee and Expense  Table on page 12,  clarify
     that under the Contracts, there are layers of fees (at the separate account
     level and at the Portfolio level).

     Response:  The requested disclosure has been added.  See attached.

5.   Comment:   In  the   "Information   About   Large   Cap"   section  of  the
     prospectus/proxy  statement,  the  discussion  references  the Statement of
     Additional  Information dated May 1, 2006 as supplemented November 1, 2006.
     Should reference also be made to a supplement dated October 2, 2006?

     Response:  Large Cap Core has a supplement  dated  November 1, 2006.  Large
     Cap's  only  supplements  are  August 16,  2006 and  October  2, 2006.  The
     disclosure is correct.

6.   Comment:  In the  paragraph  preceding  the Fee Table,  please  clarify the
     disclosure  to convey that Class A  shareholders  of Large Cap will receive
     Class A shares of Large Cap Core in the Reorganization  rather than Class E
     shares of Large Cap Core.

     Response: The requested disclosure is already in the section titled "What
     Class of Shares Will I Own?" on page 7. Additional disclosure has been
     added to footnote 3 to the Fee Table. See attached.

7.   Comment:  Footnote 4 to the Fee Table includes the following statement: "It
     is anticipated that the waiver will apply to additional  investments in the
     Portfolio."  We do  not  think  it is  appropriate  to  include  disclosure
     regarding  a  potential  waiver and  therefore  ask that the  statement  be
     deleted from footnote 4.

     Response: The above-referenced sentence has been modified as follows: "The
     Insurance Companies have agreed that the waiver will apply to additional
     investments in the Portfolio."

8.   Comment:  The last  sentence  of the first  paragraph  in the  Introductory
     Paragraph to the Pro Forma Combining  Financial  Statements is not true and
     therefore should be deleted.

     Response:  The requested sentence has been deleted.  See attached.

9.   Comment: In the Pro Forma Statement of Investments, identify all non-income
     producing securities with a footnote.

     Response:  The requested footnote has been added.  See attached.

10.  Comment:  In the Pro Forma  Statement  of  Investments,  add the  following
     statement:  "As of June 30, 2006, all portfolio  securities of the acquired
     fund  will  comply  with  the  investment  restrictions  and/or  compliance
     guidelines of the acquiring fund."

     Response:  The requested disclosure has been added.  See attached.

11.  Comment:  In the  heading  of the last  column  of the  Combined  Pro Forma
     Statement of Operations, provide the name of the acquiring fund as was done
     in the other pro forma financial statements.

     Response:  The requested column heading has been added.  See attached.

12.  Comment:  In Note 3 of the  Notes  to the  Pro  Forma  Combining  Financial
     Statements,  discuss the fund's policy with respect to valuing fixed-income
     and short-term securities.

     Response:  Additional disclosure has been added.  See attached.

                                 * * *

The Trust acknowledges that:

         1)       it is responsible for the adequacy and accuracy of the
                  disclosure in its filing of the above-referenced registration
                  statement;

         2)       staff comments or changes to disclosure in response to staff
                  comments in the filings reviewed by the staff do not foreclose
                  the Securities and Exchange Commission from taking any action
                  with respect to the filing; and

         3)       the Trust may not assert staff comments as a defense in any
                  proceeding initiated by the Securities and Exchange Commission
                  or any person under the federal securities laws of the United
                  States.

     Any  questions  or comments  with respect to this filing may be directed to
the undersigned at (202) 775-1205.

                                              Very truly yours,

                                             /s/ Robert N. Hickey
                                              Robert N. Hickey

Enclosures

cc:      Elizabeth M. Forget






                                                COMMENT 2



THESE TABLES DO NOT REFLECT THE CHARGES AND FEES ASSESSED BY THE INSURANCE
COMPANY UNDER YOUR CONTRACT.

Fees and Expenses (as a percentage of average daily net assets)





- ----------------------------- ---------------------------------------- --------------------------------------

                                             Large Cap                            Large-Cap Core
- ----------------------------- ---------------------------------------- --------------------------------------
- ----------------------------- ------------ ------------- ------------- ------------ ----------- -------------
                                Class A      Class B       Class E       Class A     Class B      Class E
                                -------      -------       -------       -------     -------      -------
- ----------------------------- ------------ ------------- ------------- ------------ ----------- -------------
- ----------------------------- ------------ ------------- ------------- ------------ ----------- -------------
                                                                                 

Management Fees                  0.49%        0.49%         0.49%         0.78%       0.78%        0.78%
- ----------------------------- ------------ ------------- ------------- ------------ ----------- -------------
- ----------------------------- ------------ ------------- ------------- ------------ ----------- -------------
Distribution and 12b-1 Fees      0.00%        0.25%         0.15%         0.00%       0.25%        0.15%
- ----------------------------- ------------ ------------- ------------- ------------ ----------- -------------
- ----------------------------- ------------ ------------- ------------- ------------ ----------- -------------
Other Expenses                   0.06%        0.06%         0.06%         0.11%       0.11%        0.11%
- ----------------------------- ------------ ------------- ------------- ------------ ----------- -------------
- ----------------------------- ------------ ------------- ------------- ------------ ----------- -------------
Total Annual Portfolio           0.55%        0.80%         0.70%         0.89%       1.14%        1.04%
Operating Expenses (1) (2)
- ----------------------------- ------------ ------------- ------------- ------------ ----------- -------------


(1) Large Cap placed certain portfolio trades with brokers who paid a portion of
Large Cap's expenses. The expense information for Large Cap does not reflect
this reduction in expenses. If this reduction was shown, Large Cap's total
annual operating expenses would have been 0.53% for Class A shares, 0.78% for
Class B shares and 0.68% for Class E shares.

(2) Met Investors Advisory, LLC (the "Manager") and the Trust have entered into
an Expense Limitation Agreement whereby the total Annual Portfolio Operating
Expenses of Large-Cap Core, other than 12b-1 fees, [interest, taxes, brokerage
commissions, other expenditures which are capitalized in accordance with
generally accepted accounting principles and other extraordinary expenses not
incurred in the ordinary course of the Portfolio's business,] will not exceed
1.00% for the period ended April 30, 2007. Assuming that the Reorganization of
Large Cap into Large-Cap Core is consummated, commencing May 1, 2007, there will
no longer be any expense limitations with respect to Large Cap Core. Under
certain circumstances, any fees waived or expenses reimbursed by the Manager
may, with the approval of the Trust's Board of Trustees, be repaid to the
Manager.






                                                  COMMENT 4

                                                  COMMENT 6



- -------------------------------- --------------------------------------
                                            Large-Cap Core
                                              (Pro Forma)
- -------------------------------- --------------------------------------
- -------------------------------- ----------- ----------- --------------
                                  Class A     Class B       Class E
- -------------------------------- ----------- ----------- --------------
- -------------------------------- ----------- ----------- --------------
Management Fees (3)                0.57%       0.57%         0.57%
- -------------------------------- ----------- ----------- --------------
- -------------------------------- ----------- ----------- --------------
Distribution and 12b-1 Fees        0.00%       0.25%         0.15%
- -------------------------------- ----------- ----------- --------------
- -------------------------------- ----------- ----------- --------------
Other Expenses                     0.05%       0.05%         0.05%
- -------------------------------- ----------- ----------- --------------
- -------------------------------- ----------- ----------- --------------
Total Annual Portfolio             0.62%       0.87%         0.77%
Operating Expenses (4)
- -------------------------------- ----------- ----------- --------------


(3) The Management Fee reduction is contingent upon the adoption of a 12b-1 Plan
for  Class A  shares  by the  Class A  shareholders  of  Large-Cap  Core and the
subsequent  conversion  of these  shares  to Class E shares of  Large-Cap  Core.
[Class A  shareholders  of Large Cap will  receive  Class A shares of  Large-Cap
Core.]


(4) [Under your Contract,  the Insurance  Company  deducts  certain charges from
your account to pay for risk and other expenses. In addition, you indirectly pay
the fees and expenses of Large Cap.] Each Insurance Company has agreed that upon
consummation  of the  Reorganization,  it will  permanently  waive  0.08% of the
Contract  charges that apply to your  investment  in Large-Cap  Core,  including
reinvestment of dividends.  The Insurance  Companies have agreed that the waiver
also will apply to additional investments in the Portfolio.

                         ------------------------------

         The tables below show examples of the total expenses you would pay on a
$10,000 investment over one-, three-, five- and ten-year periods. The examples
are intended to help you compare the cost of investing in Large Cap versus
Large-Cap Core and Large-Cap Core (Pro Forma), assuming the Reorganization takes
place. The examples assume a 5% average annual return, that you redeem all of
your shares at the end of each time period and that you reinvest all of your
dividends. The following tables also assume that total annual operating expenses
remain the same and that all expense limitations remain in effect only for the
period ended April 30, 2007 for Large-Cap Core. The examples do not reflect the
waiver of certain Contract charges by the Insurance Companies. The examples are
for illustration only, and your actual costs may be higher or lower.

         THE EXAMPLES DO NOT REFLECT THE FEES, EXPENSES OR WITHDRAWAL CHARGES
IMPOSED BY THE CONTRACTS FOR WHICH THE PORTFOLIOS SERVE AS INVESTMENT VEHICLES.
IF THOSE FEES AND EXPENSES HAD BEEN INCLUDED, YOUR COSTS WOULD BE HIGHER.




                                                      COMMENT 8


Metropolitan Series Fund, Inc.

Pro Forma Combining Financial Statements (Unaudited)
June 30, 2006

Introductory Paragraph

The pro forma statements give effect to the proposed transfer of the assets and
stated liabilities of Metropolitan Series Fund, Inc., BlackRock Large Cap
Portfolio ("BlackRock Large Cap") in exchange for shares of BlackRock Large-Cap
Core Portfolio ("BlackRock Large-Cap Core") at net asset value. Under generally
accepted accounting principles, the historical cost of investment securities
will be carried forward to the surviving entity, BlackRock Large-Cap Core, and
the results of operations of BlackRock Large-Cap Core for pre-combination
periods will not be restated.    [SENTENCE DELETED]

The pro forma unaudited combining statements of assets and liabilities and
portfolio of investments reflect the financial position of the BlackRock Large
Cap and BlackRock Large-Cap Core, as though the reorganization occurred as of
June 30, 2006.

The pro forma unaudited statement of operations reflects the results of
operations of each of the merged funds for the period ended June 30, 2006 as
though the reorganization occurred as of the beginning of the period.

The pro forma combining statements should be read in conjunction with the
financial statements and financial highlights for the BlackRock Large Cap and
BlackRock Large-Cap Core, which are incorporated by reference in the Statement
of Additional Information.





                                                         COMMENT 9

                                                         COMMENT 10





                                                                                            

Software                       Citrix Systems, Inc. *                           19,000               762,660
Software                       Intuit, Inc. *                                   23,000             1,388,970
Software                       Microsoft Corp.                                 716,200            16,687,460
Software                       Oracle Corp. *                                1,244,000            18,025,560
Software                       Red Hat, Inc. *                                  50,000             1,170,000
                                                                                              --------------
                                                                                                  50,338,900      2.8%
                                                                                              --------------

Textiles, Apparel & Luxury
Goods                          NIKE, Inc. (Class B)                             95,100             7,703,100      0.4%
                                                                                              --------------

Thrifts & Mortgage Finance     Countrywide Financial Corp.                     229,700             8,746,976
Thrifts & Mortgage Finance     Washington Mutual, Inc.                         231,300            10,542,654
                                                                                              --------------
                                                                                                  19,289,630      1.1%
                                                                                              --------------

Tobacco                        Altria Group, Inc.                              177,300            13,019,139
Tobacco                        Reynolds American, Inc.                         125,900            14,516,270
                                                                                              --------------
                                                                                                  27,535,409      1.5%
                                                                                              --------------

Wireless Telecommunication
Services                       Sprint Nextel Corp.                             539,291            10,780,427      0.6%
                                                                                              --------------

- ----------------------------------------------------------------------------------------------------------------------
Total Common Stocks                                               (Cost $1,685,415,764)        1,797,597,764     98.9%
- ----------------------------------------------------------------------------------------------------------------------
                                                                                                           0

Escrowed Shares                ESC Seagate Technology                           27,200                    27      0.0%
- ----------------------------------------------------------------------------------------------------------------------
Total Escrowed Shares                                                         (Cost $0)                   27      0.0%
- ----------------------------------------------------------------------------------------------------------------------
Short-Term Investment          State Street Navigator
                               Securities Lending Prime
                               Portfolio                                    62,732,810            62,732,810      3.4%
- ----------------------------------------------------------------------------------------------------------------------
Total Short-Term Investment                                          (Cost $62,732,810)           62,732,810      3.4%
- ----------------------------------------------------------------------------------------------------------------------

- ----------------------------------------------------------------------------------------------------------------------
TOTAL INVESTMENTS                                                 (Cost $1,748,108,574)        1,860,330,601    102.3%
- ----------------------------------------------------------------------------------------------------------------------
Other Assets and Liabilities
(Net)                                                                         (144,200)(a)       (41,875,944)    -2.3%
- ----------------------------------------------------------------------------------------------------------------------
TOTAL NET ASSETS - 100.0%                                                     (144,200)(a)    $1,818,454,657    100.0%
======================================================================================================================


[*     Non-income producing security. ]

[As of June 30, 2006, all portfolio securities of the acquired fund will comply]
[with the investment restrictions and/or compliance guidelines of the acquiring]
[fund.





                                                       COMMENT 11




Met Investors SEries Trust
COMBINED PRO FORMA STATEMENT OF OPERATIONS

For the twelve month period ended June 30, 2006 (UNAUDITED)



                                                                                                              [ Met Investors
                                                                                                                Series Trust
                                                                                                                  BlackRock
                                                                                          Adjustments          Large-Cap Core
                                                                                        (References are           Portfolio ]
                                                                                          to Pro Forma            Pro Forma
                                                                                           Footnotes)             Combined
                                                                                        ----------------       ---------------
                                                                                                         
Investment Income
      Dividend                                                                                         0            34,625,309
      Interest                                                                                         0               460,529(a)
                                                                                        ----------------       ---------------
                                                                                                       0            35,085,838
Expenses
      Management fees                                                                          4,082,279(b)         13,936,410
      Deferred Expense Reimbursement                                                                                        --
      Service and distribution fees-Class B                                                                             84,206
      Service and distribution fees-Class E                                                                             68,194
      Administration fees                                                                                               67,781
      Directors fees and expenses                                                                (22,541)(c)            23,736
      Custodian                                                                                  (20,056)(c)           387,620
      Transfer agent fees                                                                         44,962(c)             48,000
      Audit and tax services                                                                     (17,860)(c)            36,241
      Legal                                                                                      (27,667)(c)            34,641
      Printing                                                                                  (297,264)(c)           251,023
      Insurance                                                                                  (29,269)(c)            26,000
      Organizational Expense                                                                          --
      Miscellaneous expenses                                                                     (35,434)(c)            14,000
                                                                                        ----------------       ---------------
          Total Expenses                                                                       3,677,150            14,977,852
      Expense Reductions                                                                         381,325(c)                 --
      Expense assumed by the Investment Adviser                                                   10,662(c)                 --
                                                                                        ----------------       ---------------
      Net Expenses                                                                             4,069,137            14,977,852
                                                                                        ----------------       ---------------
      Net Income                                                                              (4,069,137)           20,107,986
Realized and Unrealized Gain (Loss) on Investments

      Net realized gain (loss) on investments                                                          0            92,635,739
      Net realized gain (loss) on foreign currency transactions                                        0                   191
      Net realized gain (loss) on futures transactions                                                 0              (142,114)
                                                                                        ----------------       ---------------
         Net realized gain (loss) on investments, foreign currency,
            and futures transactions                                                                   0            92,493,816

      Net unrealized appreciation (depreciation) on investments                                        0             1,265,862
      Net unrealized appreciation (depreciation) on foreign currency transactions                      0                   336
      Net unrealized appreciation (depreciation) on futures transactions                               0               488,891
                                                                                        ----------------       ---------------
      Net unrealized gain (loss) on investments, foreign currency,
            and futures transactions                                                                   0             1,755,089
                                                                                        ----------------       ---------------

      Net gain (loss)                                                                                  0            94,248,905

Net increase (decrease) in Net Assets from Operations                                   $     (4,069,137)      $   114,356,891
                                                                                        ================       ===============

- ------------------------------------------------------------------------------------------------------------------------------

(a)  Includes income fom securities loaned                                             $              0       $        44,197

(b)   Reflects the BlackRock Large-Cap Core Portfolio's investment advisory fee
      rate.

(c)   Reflects adjustment of certain balances to conform to the MIST BlackRock
      Large-Cap Core Portfolio's expense structure.







                                                     COMMENT 12



MET INVESTORS SERIES TRUST

Notes to Pro Forma Combining Financial Statements (Unaudited)
June 30, 2006

1     Description of the Fund

      The BlackRock Large-Cap Core Portfolio ("BlackRock Large-Cap Core") a
      portfolio of Met Investors Series Trust is registered under the Investment
      Company Act of 1940, as amended, as an open-end, diversified investment
      company.

      BlackRock Large-Cap Core consists of three classes of shares, Class A,
      Class B, and Class E. The classes of shares are identical except that
      certain additional charges (Rule 12b-1 fees) are made against Class B and
      E shares.

2     Basis of Combination

      The pro forma statements give effect to the proposed transfer of the
      assets and stated liabilities of Metropolitan Series Fund, Inc., BlackRock
      Large Cap Portfolio ("BlackRock Large Cap") in exchange for shares of
      BlackRock Large-Cap Core Portfolio at net asset value. Under generally
      accepted accounting principles, the historical cost of investment
      securities will be carried forward to the surviving entity, BlackRock
      Large-Cap Core, and the results of operations of BlackRock Large-Cap Core
      for pre-combination periods will not be restated.

      The pro forma combined financial statements reflect the expenses of the
      portfolio in carrying out its obligations under the proposed Agreement and
      Plan or Reorganization.

      The pro forma unaudited combining statements of assets and liabilities and
      portfolio of investments reflect the financial position of the and
      BlackRock Large-Cap Core, as though the reorganization occurred as of June
      30, 2006.

      The pro forma unaudited statement of operations reflects the results of
      operations of each of the merged funds for the period ended June 30, 2006
      as though the reorganization occurred as of the beginning of the period.

      The pro forma combining statements should be read in conjunction with the
      financial statements and financial highlights for the BlackRock Large Cap
      and BlackRock Large-Cap Core, which are incorporated by reference in the
      Statement of Additional Information.

3     Portfolio Valuation

      Equity securities traded on a national securities exchange or exchanges
      are valued at their last sale price on the principal trading market.
      Equity securities traded on the NASDAQ National Market System are valued
      at the NASDAQ Official Closing Price (the "NOCP"). The NOCP is the last
      sale price if it falls between the spread of the last reported bid and
      asked prices. If the last reported bid and asked prices are above the last
      reported sale price, the NOCP will be the last reported bid price. If the
      last reported bid and asked prices are below the last reported sale price,
      the NOCP will be the last reported asked price. Equity securities traded
      on a national securities exchange or exchanges or on the NASDAQ National
      Market System for which there is no reported sale during the day, are
      valued at the last reported bid price. A security that is listed or traded
      on more than one exchange is valued at the quotation on the exchange
      determined to be the primary market for that security by the Board or its
      delegates. If no closing price is available, then such securities are
      valued by using the last reported bid price.

      Equity securities traded over-the-counter are valued at the last reported
      bid price. Foreign securities traded outside the United States will be
      valued daily at their fair value according to procedures decided upon in
      good faith by the Trust's Board of Trustees. All securities and other
      assets of a Portfolio initially expressed in foreign currencies will be
      converted to U.S. dollar values at the mean of the bid and offer prices of
      such currencies against U.S. dollars quoted as designated on the Price
      Source Authorization Agreement between the Trust and its custodian on a
      valuation date by any recognized dealer. [Short-term securities with
      remaining maturities of less than 60 days are valued at amortized cost,
      which approximates market value.]

4     Federal Income Taxes

      Each Fund has elected to be taxed as a regulated investment company. After
      the acquisition, the BlackRock Large-Cap Core intends to continue to
      comply with the requirements of the Internal Revenue Code and regulations
      hereunder applicable to regulated investment companies and to distribute
      all of its taxable income to shareholders. Therefore, no federal income
      tax provision is required. The tax cost of investments will remain
      unchanged for the combined fund.

5     Estimates and Assumptions:

      The preparation of financial statements in conformity with GAAP requires
      management to make estimates and assumptions that affect the reported
      amounts of assets and liabilities and disclosure of contingent assets and
      liabilities as of the date of the financial statements and the reported
      amounts of income and expenses during the reporting period. Actual results
      could differ from those estimates.