Daiichi Sankyo Company of Japan announced plans to take a majority stake in Ranbaxy Labs for $3.4 billion to $4.6 billion. A patent settlement with Pfizer for Ranbaxy to market a generic version of Lipitor after November 2011 may be part of the effort to give more clarity to Daiichi Sankyo for it to go ahead with the deal. Both Pfizer and Ranbaxy have extensive litigation on this issue. Pfizer could otherwise have seen Ranbaxy bring a generic version of Lipitor in March 2010. About 25% of Pfizer's $48 billion in revenues come from Lipitor and its stock price is at its lowest in a decade because of the uncertainty over Lipitor. Under the agreement Ranbaxy gets to be the only company to market a generic version of Lipitor for 180 days after Pfizer's patent expires. Ranbaxy also gets to market a generic version of Caduet, a pill that combines Lipitor and blood pressure medication Norvasc, in 2011 before the patent for Caduet expires in 2018. The FDA can question the terms of this agreement as it favors introduction of generics competition, and the Caduet portion of this deal may be seen as a payoff to Ranbaxy for settling with Pfizer....