Sanofi-Aventis and Merck: Top 10 deals of 2009

Who: Sanofi-Aventis
With: Merck
What: $4B buyout

Summary: Last summer, Sanofi-Aventis bought the rest of Merial, its animal health joint venture with Merck, for $4 billion. And Sanofi negotiated an option to join forces again after Merck and Schering-Plough merge, combining Merial and Schering's animal health business Intervet. Under the option Sanofi would pay $9.25 billion to joint venture with Intervet, which would be owned equally by Merck and Sanofi. "The combination would create a new leader in this $19 billion global animal health market, supporting our vision of a global diversified healthcare leader." Sanofi CEO Christopher Viehbacher said at the time.