Merck and Schering-Plough to Complete Merger Today

* New Merck Will Begin Combined Operations Tomorrow

* Global Health Care Leader Poised for Sustainable Growth Through Innovations for Patients

WHITEHOUSE STATION and KENILWORTH, N.J.- – Merck & Co., Inc. (NYSE: MRK) and Schering-Plough Corporation (NYSE: SGP) today announced that they will complete their merger shortly after 4:00PM ET today. The companies will begin combined operations tomorrow, November 4, 2009. As previously announced, Schering-Plough will change its name to Merck and its common stock will trade under the ticker symbol “MRK” on the New York Stock Exchange.

Under the terms of the agreement, Schering-Plough shareholders will receive 0.5767 shares of the newly combined company and $10.50 in cash for each share of Schering-Plough. Each Merck common share will automatically become a common share of the newly combined company.

This announcement follows clearance from regulatory authorities in China and Mexico. The merger of local Merck and Schering-Plough entities may be pending in other jurisdictions and integration is subject to completion of various local legal and regulatory obligations.

From the completion of the merger today through 5:00 p.m. ET on November 19, 2009, the 6.00% Mandatory Convertible Preferred Stock of Schering-Plough will be convertible at a make-whole conversion rate of 8.2021. For each share of preferred stock converted during this period, the holder will receive $86.12 in cash ($10.50 x 8.2021) and 4.7302 “MRK” common shares (0.5767x 8.2021). Holders will also receive, for each share converted, a dividend make-whole payment of between $10.79 and $10.82, depending on the date of conversion. Additional information regarding the make-whole conversion rights of the holders of the preferred stock is set forth in the “Notice of Make-Whole Acquisition” available at www.schering-plough.com. Beginning tomorrow, the 6.00% Mandatory Convertible Preferred Stock will trade under the ticker symbol “MRK PR B”.

Merck has appointed Wells Fargo Shareowner Services as agent to exchange the Schering-Plough common stock for merger consideration and as conversion agent for the 6.00% Mandatory Convertible Preferred Stock. Schering-Plough registered shareholders with questions regarding the exchange of Schering-Plough common stock for merger consideration or the conversion of the 6.00% Mandatory Convertible Preferred Stock should contact Wells Fargo Shareowner Services at (800) 522-9114.

Additional information regarding the exchange of Schering-Plough common stock for merger consideration will also be mailed to registered holders of Schering-Plough common stock. Schering-Plough shareholders who hold shares through a broker or bank should receive information regarding the exchange or conversion of their shares from the party holding their shares.