PARIS, FRANCE and WHITEHOUSE STATION, N.J., Sept. 18, 2009 - Sanofi-aventis (EURONEXT: SAN and NYSE: SNY) and Merck & Co., Inc. (NYSE: MRK) today announced that the acquisition by sanofi-aventis of Merck’s 50 percent interest in Merial Limited (Merial) has been completed.

Sanofi-aventis acquired Merck’s interest in Merial for a cash consideration of $4 billion (US). Formed in 1997, Merial is a leading animal health company that was a 50/50 joint venture between Merck and sanofi-aventis and is now a wholly-owned subsidiary of sanofi-aventis.

As per the terms of the agreement signed on July 29, 2009, sanofi-aventis also has an option, following the closing of the Merck/Schering-Plough merger, to combine the Intervet/Schering-Plough Animal Health business with Merial to form an animal health joint venture that would be equally owned by the new Merck and sanofi-aventis. If the option is exercised by sanofi-aventis, the formation of the new animal health joint venture would be subject to approval by the relevant competition authorities.

The acquisition of Merial is expected to be accretive to sanofi-aventis' adjusted net income from the first year.

Christopher A. Viehbacher, chief executive officer of sanofi-aventis declared: “I am very happy to welcome Merial in the sanofi-aventis family. This acquisition strengthens sanofi-aventis’ position in the attractive animal health market. It illustrates our strategy to grow and diversify our business in order to become a global diversified healthcare leader with a sustainable growth and a reduced risk-profile.”

"The sale of Merck's interest in Merial allows us to remain on track for the closing of our merger with Schering-Plough in the fourth quarter, as planned," said Richard T. Clark, chairman, president and chief executive officer. "With the new Merck, we look forward to gaining a strong market presence and pursuing valuable growth opportunities in the animal health sector."

Merial will report to Hanspeter Spek, executive vice president, Global Operations, sanofi-aventis.

In 2008, Merial ranked number three in the animal health market with sales of $ 2.7 billion and a market share estimated at 13.8 percent.

About Merck
Merck & Co., Inc. is a global research-driven pharmaceutical company dedicated to putting patients first. Established in 1891, Merck discovers, develops, manufactures and markets vaccines and medicines to address unmet medical needs. The Company devotes extensive efforts to increase access to medicines through far-reaching programs that not only donate Merck medicines but help deliver them to the people who need them. Merck also publishes unbiased health information as a not-for-profit service. For more information, visit www.merck.com.

About sanofi-aventis
Sanofi-aventis, a leading global pharmaceutical company, discovers, develops and distributes therapeutic solutions to improve the lives of everyone. Sanofi-aventis is listed in Paris (EURONEXT: SAN) and in New York (NYSE: SNY).

About Merial
Merial is a world-leading, innovation-driven animal health company, providing a comprehensive range of products to enhance the health, well-being and performance of a wide range of animals. Merial employs approximately 5,700 people and operates in more than 150 countries worldwide. Merial Limited is a subsidiary of sanofi-aventis. For more information, please see www.merial.com