NORTHWESTERN MUTUAL SERIES FUND, INC. April 27, 2007

Exhibit (h)9

NORTHWESTERN MUTUAL SERIES FUND, INC.

April 27, 0000

Xxxxx Xxxxxx Advisors, LLC

000 Xxxx Xxxxxxxxx Xxxxxx

Xxxxxxxxx, XX 00000

Re: Agreement to Waive Xxxxx Street Advisors, LLC Investment Advisory Fees Relating to the Asset Allocation Portfolio

Gentlemen:

This letter constitutes an agreement between Xxxxx Street Advisors, LLC (“MSA”) and Northwestern Mutual Series Fund, Inc. (“NMSF”) by and between each of the parties hereto regarding the Investment Advisory Fee for the Asset Allocation Portfolio (“Portfolio”). Effective as of the close of business on the date hereof, and ending on May 1, 2008 (unless renewed by the parties hereto), MSA agrees to waive its Investment Advisory Fee applicable to the Portfolio such that its management is as follows:

Assets		Fee
First $100 million		0.55	%
$100 million - $250 million		0.45	%
Over $250 million		0.35	%

Very truly yours,
NORTHWESTERN MUTUAL SERIES FUND, INC.
By:		/s/ XXXX X. XXXXXXX
Name:		Xxxx X. Xxxxxxx
Title:		Vice President

Agreed to and accepted:
XXXXX STREET ADVISORS, LLC
By:		/s/ XXXX X. XXXX
Name:		Xxxx X. Xxxx
Title:		President