SEATTLE, June 20, 2008 (PRIME NEWSWIRE) -- Keller Rohrback L.L.P. (www.erisafraud.com), Co-Lead Counsel for the ERISA plaintiffs in the In re Merck & Co. Inc. Securities, Derivative, & ERISA Litigation, MDL No. 1658, pending in the U.S. District Court for the District of New Jersey, announces that it has commenced an expanded investigation against Merck & Co. Inc. ("Merck" or the "Company") (NYSE:MRK) for potential violations of the Employee Retirement Income Security Act of 1974 ("ERISA"). The expanded investigation involves concerns that Merck may have breached its ERISA-mandated fiduciary duties in relation to the Merck 401K Plans' investments in the Merck Common Stock Fund that were made during the time period of July 26, 2004 through March 31, 2008. If you are or were a participant in the Merck & Co., Inc. Employee Savings & Security Plan, the Merck & Co., Inc. Employee Stock Purchase & Savings Plan, or the Merck Puerto Rico Employee Savings & Security Plan during the July 26, 2004 through March 31, 2008 time frame, and were invested in the Merck Common Stock Fund, and would like further information about our investigation, please contact attorney Amy Hanson at (206) 224-7435 or toll free at (800) 776-6044, or via e-mail at ahanson@kellerrohrback.com.

Our expanded investigation includes, but is not limited to, whether Merck may have failed to disclose known material information about the efficacy of Vytorin to Merck's 401K plan participants at the time that it was publicly touting Vytorin as a superior cholesterol treatment. When the results of Merck's clinical trial of Vytorin were made public earlier this year, the Plans and Plan participants suffered massive losses as Merck's stock price and the price of the Merck Common Stock Fund held by the Merck 401K Plans decreased substantially. Merck may have breached its fiduciary duties to prudently and loyally invest and maintain the assets of the Merck 401K Plans, as well as its fiduciary duty to provide adequate information to the participants of those plans, by its actions and omissions (including but not limited to its conduct in relation to Vytorin) that materially affected the Merck 401K Plans' holdings of Merck stock during the July 26, 2004 through March 31, 2008 time period.

Keller Rohrback L.L.P. is one of America's leading law firms handling ERISA retirement plan litigation. We are committed to helping employees and retirees protect their retirement savings. Keller Rohrback L.L.P. serves as lead and co-lead counsel in numerous ERISA class action cases, including cases against Merck, Enron, WorldCom, Inc., and Merrill Lynch. Its trial lawyers have obtained judgments and settlements on behalf of clients in excess of seven billion dollars.

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CONTACT:  Keller Rohrback L.L.P.
          Amy Hanson, Attorney
          800-776-6044 
          206-224-7435
          ahanson@kellerrohrback.com
          www.erisafraud.com