Exhibit 10.1 DOW CORNING LETTERHEAD March 30, 2004 ACCNO.: 30182 Genencor International, Inc. 925 Page Mill Road Palo Alto, CA 94304 Attn: General Counsel To Whom It May Concern: This will refer to the Research Agreement between Dow Corning Corporation and Genencor International, Inc. dated October 4, 2001 and the extension dated February 11, 2003, and December 16, 2003, relating to research in the areas of biosensors, bioenergy, biomaterials, bioalkylation, biocatalysis, silicon-based materials, bioseparations and formulations. The present Agreement expires on March 31, 2004. Assuming Genencor International, Inc. wishes to continue working with Dow Corning Corporation, we propose to extend the term of the above-mentioned Agreement two (2) additional months. The new expiration date will be May 31, 2004. No additional Milestone payments are due from Dow Corning during the time period of this Extension. All other terms and conditions of the Agreement will remain the same. If the above meets with your approval, please have both copies of this letter signed by an authorized officer of Genencor International, Inc. and return one fully executed original to: Contract Team (CO1232) Dow Corning Corporation Law Department 2200 W. Salzburg Road P.O. Box 994 Midland, MI 48686-0994 If you have any questions about this proposal please call the Dow Corning contact for this agreement, Dave Cornelius at (989) 496-3265. Very truly yours, ACCEPTED DOW CORNING CORPORATION GENENCOR INTERNATIONAL, INC. By: /s/ Gregg A. Zank By: /s/ Michael V. Arbige ----------------------- --------------------- Name: Gregg A. Zank Name: Michael V. Arbige ----------------------- ----------------- Title: Executive Director Title: Sr. Vice President, Technology ----------------------- ------------------------------ Date: 1, April, 2004 Date: 4/8/04 ----------------------- ------ cc: David J. Cornelius, Dow Corning (CO43M1)