On March 19, 2009, Merrimac Industries, Inc. (the "Company") and American Stock Transfer & Trust Company, LLC, as Rights Agent (the "Rights Agent"), executed the ninth amendment (the "Amendment") to the Company's Rights Agreement (the "Rights Agreement"), dated as of March 9, 1999, as amended as of June 9, 1999, April 7, 2000, October 26, 2000, February 21, 2001, February 28, 2002, September 18, 2002, December 13, 2004 an March 14, 2007. The Amendment extended the expiration date of the Rights Agreement from March 19, 2009 to December 31, 2009.

The foregoing description of the Amendment does not purport to be complete and is qualified in its entirety by reference to the Amendment, which is attached as Exhibit 4.1 to this Form 8-K and is incorporated herein by reference.

(d) Exhibits.

Exhibit No. Description

4.1          Amendment No. 9 to the Company's Rights Agreement, dated as of March
             19, 2009, between the Company and American Stock Transfer & Trust
             Company, LLC.