<PAGE>

                                                                   EXHIBIT 10.25

                       FIRST AMENDMENT TO CREDIT AGREEMENT

         THIS FIRST AMENDMENT TO CREDIT AGREEMENT, dated as of December 19, 2003
(this "Amendment"), amends the Credit Agreement, dated as of April 23, 2002 (the
"Credit Agreement"), among METLIFE, INC., METROPOLITAN LIFE INSURANCE COMPANY
and METLIFE FUNDING, INC., as borrowers, certain Lenders party hereto (the
"Lenders"), BANK ONE, NA, CITIBANK N.A., JP MORGAN CHASE BANK AND WACHOVIA BANK,
N.A., as Co-Syndication Agents, and BANK OF AMERICA, N.A., as Administrative
Agent (the "Administrative Agent") for the Lenders. Terms defined in the Credit
Agreement are, unless otherwise defined herein or the context otherwise
requires, used herein as defined therein.

         WHEREAS, the parties hereto have entered into the Credit Agreement,
which provides for the Lenders to extend certain credit facilities to the
Borrowers from time to time; and

         WHEREAS, the parties hereto desire to amend the Credit Agreement in
certain respects as hereinafter set forth;

         NOW, THEREFORE, in consideration of the premises and for other good and
valuable consideration (the receipt and sufficiency of which are hereby
acknowledged), the parties hereto agree as follows:

         SECTION 1. AMENDMENT. Effective as of the date hereof,

         1.1      Definition. The definition of "L/C Commitment" in Section 1.1
of the Credit Agreement is hereby amended to state in its entirety as follows:

                  "L/C Commitment" means the commitment of each Lender to
                  severally Issue Letters of Credit from time to time under
                  Article III, in an amount not to exceed at any time
                  outstanding the amount set forth on Schedule 2.1, as reduced
                  pursuant to Section 2.7 or changed by one or more assignments
                  under Section 10.4. The combined L/C Commitments on the date
                  of the First Amendment hereto are $500,000,000."

         1.2      Schedule 2.1. Schedule 2.1 of the Credit Agreement is hereby
amended to state in its entirety as set forth in Schedule 2.1 hereto.

         SECTION 2. CONDITIONS PRECEDENT. This Amendment shall become effective
when the Administrative Agent shall have received all of the following documents
duly executed, dated the date hereof or such other date as shall be acceptable
to the Administrative Agent, and in form and substance satisfactory to the
Administrative Agent:

         (a)      Amendment. This Amendment, duly executed by the Borrowers, the
Issuing Lender, the Administrative Agent and the Required Lenders.

         (b)      Secretary's Certificate. A certificate of the secretary or an
assistant secretary of each Borrower, as to (i) resolutions of the Board of
Directors of such

<PAGE>

Borrower then in full force and effect authorizing the execution, delivery and
performance of this Amendment and each other document described herein, and (ii)
the incumbency and signatures of those officers of such Borrower authorized to
act with respect to this Amendment and each other document described herein.

         SECTION 3. REPRESENTATIONS AND WARRANTIES. To induce the Lenders and
the Administrative Agent to enter into this Amendment, the Borrowers hereby
represent and warrant to the Administrative Agent and each Lender as follows:

         3.1      Due Authorization, Non-Contravention, etc. The execution,
delivery and performance by the Borrowers of this Amendment are within the
Borrowers corporate powers, have been duly authorized by all necessary corporate
action, and do not

                  (a) contravene the Borrowers' charters, by-laws or other
         organizational documents;

                  (b) contravene any contractual restriction, law or
         governmental regulation or court decree or order binding on or
         affecting the Borrowers; or

                  (c) result in, or require the creation or imposition of, any
         Lien on any of the Borrowers' properties.

         3.2      Government Approval, Regulation, etc. No authorization or
approval or other action by, and no notice to or filing with, any governmental
authority or regulatory body or other Person is required for the due execution,
delivery or performance by the Borrowers of this Amendment.

         3.3      Validity, etc. This Amendment constitutes the legal, valid and
binding obligation of the Borrowers enforceable in accordance with its terms,
subject to applicable bankruptcy, insolvency, reorganization, moratorium or
other laws affecting creditors' rights generally and subject to general
principles of equity, regardless of whether considered in a proceeding in equity
or at law.

         SECTION 4. MISCELLANEOUS.

         4.1      Continuing Effectiveness, etc. This Amendment shall be deemed
to be an amendment to the Credit Agreement, and the Credit Agreement, as amended
hereby, shall remain in full force and effect and is hereby ratified, approved
and confirmed in each and every respect. After the effectiveness of this
Amendment in accordance with its terms, all references to the Credit Agreement
in the Loan Documents or in any other document, instrument, agreement or writing
shall be deemed to refer to the Credit Agreement as amended hereby.

         4.2      Payment of Costs and Expenses. The Borrower agrees to pay on
demand all expenses of the Administrative Agent (including the fees and
out-of-pocket expenses of counsel to the Administrative Agent) in connection
with the negotiation, preparation, execution and delivery of this Amendment.

                                       2
<PAGE>

         4.3      Severability. Any provision of this Amendment which is
prohibited or unenforceable in any jurisdiction shall, as to such provision and
such jurisdiction, be ineffective to the extent of such prohibition or
unenforceability without invalidating the remaining provisions of this Amendment
or affecting the validity or enforceability of such provision in any other
jurisdiction.

         4.4      Headings. The various headings of this Amendment are inserted
for convenience only and shall not affect the meaning or interpretation of this
Amendment or any provisions hereof.

         4.5      Execution in Counterparts. This Amendment may be executed by
the parties hereto in several counterparts, each of which shall be deemed to be
an original and all of which shall constitute together but one and the same
agreement.

         4.6      Governing Law. THIS AMENDMENT SHALL BE DEEMED TO BE A CONTRACT
MADE UNDER AND GOVERNED BY THE INTERNAL LAWS OF THE STATE OF NEW YORK.

         4.7      Successors and Assigns. This Amendment shall be binding upon
and shall inure to the benefit of the parties hereto and their respective
successors and assigns.

                                       3
<PAGE>

IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be executed
by their respective officers thereunto duly authorized as of the day and year
first above written.

                                    METLIFE, INC.
                                    /s/ Anthony J. Williamson
                                    ------------------------------------------
                                    By: Anthony J. Williamson
                                    Title: Senior Vice President and Treasurer

                                    METROPOLITAN LIFE INSURANCE COMPANY
                                    /s/ Anthony J. Williamson
                                    ------------------------------------------
                                    By: Anthony J. Williamson
                                    Title: Senior Vice President and Treasurer

                                    METLIFE FUNDING, INC.
                                    /s/ Anthony J. Williamson
                                    ------------------------------------------
                                    By: Anthony J. Williamson
                                    Title: Chairman, President and
                                           Chief Executive Officer


                                       S-1
<PAGE>

                                    BANK OF AMERICA, N.A.,
                                    individually and as Administrative Agent,

                                    By: /s/ Leslie Nannen
                                        --------------------------------------
                                        Title: Vice President

                                      S-2
<PAGE>

                                    BANK ONE, NA

                                    By: /s/ Gretchen Roetzer
                                        ---------------------------
                                        Title: Director

                                      S-3
<PAGE>

                                    CITIBANK, N.A.

                                    By: /s/ David A. Dodge
                                        ---------------------------
                                        Title: Managing Director

                                      S-4
<PAGE>

                                    JPMORGAN CHASE BANK

                                    /s/ Heather Lindstrom
                                    ------------------------------
                                    By:    Heather Lindstrom
                                    Title: Vice President

                                      S-5
<PAGE>

                                    WACHOVIA BANK, NATIONAL ASSOCIATION

                                    /s/ Kimberly Shaffer
                                    -----------------------------
                                    By: Kimberly Shaffer
                                    Title: Director

                                      S-6
<PAGE>

                                    THE NORTHERN TRUST COMPANY

                                    /s/ Eric Dybing
                                    ------------------------------------
                                    By: Eric Dybing
                                    Title: Second Vice President
                                           The Northern Trust Company

                                      S-7
<PAGE>

                                    DEUTSCHE BANK AG, NEW YORK BRANCH

                                    By:
                                    Title:

                                    By:
                                    Title:

                                      S-8
<PAGE>

                                    ROYAL BANK OF CANADA

                                    /s/ A. Birr
                                    -----------------------------
                                    By: Alexander Birr
                                    Title: Authorized Signatory

                                      S-9
<PAGE>

                                    CREDIT SUISSE FIRST BOSTON
                                    Acting through its Cayman Islands Branch

                                      /s/ Jay Chall
                                      -------------------------------
                                      By:     Jay Chall
                                      Title:  Director

                                      /s/ Cassandra Droogan
                                      -------------------------------
                                      By:     Cassandra Droogan
                                      Title:  Associate


                                      S-10
<PAGE>

                                    U.S. BANK NATIONAL ASSOCIATION

                                    By:
                                    Title:

                                      S-11
<PAGE>

                                    FLEET NATIONAL BANK

                                    /s/ Marcio Chapina
                                    ------------------------------
                                    By:    Marcio Chapina
                                    Title: Vice President

                                      S-12
<PAGE>

                                    MELLON BANK, N.A.

                                    /s/ Carrie Burnham
                                    -------------------------------
                                    By:     Carrie Burnham
                                    Title:  Assistant Vice President

                                      S-13
<PAGE>

                                    BNP PARIBAS

                                    /s/ Laurent Vanderzyppe
                                    ----------------------------
                                    By:    Laurent Vanderzyppe
                                    Title: Director


                                    /s/ Phil Truesdale
                                    ----------------------------
                                    By:    Phil Truesdale
                                    Title: Director

                                      S-14
<PAGE>

                                    PNC BANK, NATIONAL ASSOCIATION

                                    /s/ Kirk Seagers
                                    -------------------------------
                                    By:    Kirk Seagers
                                    Title: Vice President & Director

                                      S-15
<PAGE>

                                    STATE STREET BANK AND TRUST COMPANY



                                    By:     /s/ Illegible
                                    Title:  Vice President

                                      S-16
<PAGE>

                                    LEHMAN COMMERCIAL PAPER, INC.

                                   /s/ Jane E. Gillard
                                   --------------------------------
                                   By: Jane E. Gillard
                                   Title: Authorized Signatory

                                      S-17
<PAGE>

                                  Schedule 2.1

                         COMMITMENTS AND L/C COMMITMENTS

<TABLE>
<CAPTION>
              Lender                    Commitment    L/C Commitment
-----------------------------------  ---------------  --------------
<S>                                  <C>              <C>
Bank of America, N.A.                $   110,000,000  $    44,000000
Bank One, NA                         $    97,500,000  $   39,000,000
Citibank, N.A.                       $    97,500,000  $   39,000,000
JPMorgan Chase Bank                  $    97,500,000  $   39,000,000
Wachovia Bank, NA                    $    97,500,000  $   39,000,000
BNP Paribas                          $    85,000,000  $   34,000,000
Credit Suisse First Boston           $    85,000,000  $   34,000,000
Deutsche Bank AG, New York Branch    $    85,000,000  $   34,000,000
Lehman Commercial Paper, Inc.        $    85,000,000  $   34,000,000
Fleet National Bank                  $    70,000,000  $   28,000,000
Mellon Bank, N.A.                    $    70,000,000  $   28,000,000
The Northern Trust Company           $    70,000,000  $   28,000,000
State Street Bank and Trust Company  $    50,000,000  $   20,000,000
U.S. Bank National Association       $    50,000,000  $   20,000,000
Royal Bank of Canada                 $    50,000,000  $   20,000,000
PNC Bank, NA                         $    50,000,000  $   20,000,000

COMMITMENTS                          $ 1,250,000,000  $  500,000,000
</TABLE>

                                        1