Exhibit 99.22(h)(vi)

[FORM]

April __, 2005


DST Systems, Inc.
1055 Broadway, 7th Floor
Kansas City, MO  64105
Attn:  Group Vice President - Full Service

Dear Sir or Madam:

     Lord Abbett Series Fund, Inc., as a party to the Agency Agreement by and
between the Lord Abbett Family of Funds and DST Systems, Inc. dated July 1, 2004
(the "Agreement"), requests an amendment to the Agreement pursuant to Sections
20.14, 2.3, and 2.2.

     Section 20.14 provides that the Agreement may be "amended, supplemented, or
modified only by an amendment." Section 2.3 of the Agreement provides that, "In
the event that a ... new series of a Fund is created in any existing business
trust...which is registered as an Investment Company under the 1940 Act on the
Agent's System as of the Execution Date, such ...series thereof shall engage the
Agent to perform the Services under this Agreement by executing and delivering
to the Agent a document accepting this Agreement (including giving effect to all
Amendments and Service Orders that have become effective after the Execution
Date), together with such documentation as is described by Section 2.2
[(captioned "Documentation")] and otherwise appropriate. The appointment of the
Agent on behalf of...any new series of a Fund shall become effective upon the
Agent's receipt of such counterpart executed by such ...series of a new Fund."

     This letter is to notify DST Systems, Inc. that on March 10, 2005, the
Fund's Board executed Articles Supplementary to Articles of Incorporation
establishing a new Series of the Fund, (the "Series") the legal name of which is
as follows: Lord Abbett Large-Cap Core Fund. It is the Fund's desire to have DST
Systems render services as transfer agent, dividend disbursing agent, and
shareholder servicing agent to the Series under the terms of the Agreement;
therefore, the Fund requests that DST Systems, Inc. agree, in writing, to
provide such services to the Series thereby making the Series a Series under the
terms of the Agreement.

     Attached is a Secretary's Certificate and accompanying resolutions and
documentation in accordance with the Agreement.

     It is currently anticipated that the registration statement for the
Large-Cap Core Fund will become effective on April 13, 2005. Accordingly, we
appreciate your prompt attention to this matter. Please indicate DST Systems,
Inc.'s acceptance by signing below.

                                        Lord Abbett Series Fund, Inc.


                                        --------------------------------
                                        Paul A. Hilstad
                                        Vice President and Secretary

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Accepted:


----------------------------------------
Group Vice President - Full Service
DST Systems, Inc.

Enclosures

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