Sanofi, Bristol shake up alliance as patents end PARIS (Reuters) - Drugmakers Sanofi and Bristol-Myers Squibb said they plan to restructure their alliance from January 1 to respond to the loss of exclusivity on two key drugs and the arrival of generic competition in many major markets. The move will see Bristol-Myers return rights to blood clot preventer Plavix and blood pressure treatment Avapro to the French drugmaker in all markets, the companies said in a joint statement on Wednesday. This will give Sanofi sole commercial control of the two treatments, although Bristol-Myers will keep rights to Plavix in the United States and Puerto Rico. In return, Sanofi will pay Bristol-Myers royalty payments through 2018 on its sales of branded and unbranded Plavix worldwide, excluding the U.S. and Puerto Rico, and on sales of Avapro/Avalide. Sanofi will also make a $200 million terminal payment to Bristol-Myers at the end of 2018, the companies said. Plavix had been the world's second-biggest selling prescription medicine for several years with annual revenue reaching about $9 billion at its peak. Reporting by James Regan; Editing by David Cowell