NEW YORK: Pfizer Inc, the world’s largest pharmaceutical company by revenue, said Tuesday it will buy pain drug maker King Pharmaceuticals Inc. for $3.6 billion in cash.Pfizer is paying $14.25 per share for King. That’s a premium of 40 percent to the stock’s Monday closing price of $10.15. Pfizer gains products including the pain drug Avinza, and Embeda, an extended-release pain treatment that is designed to be abuse-resistant.King, of Bristol, Tennessee, has struggled in recent years as patents on several of its key drugs have expired or been thrown out.The boards of both companies approved the deal. Pfizer said the purchase will add about 2 cents per share to its profit in 2011 and 2012, and 3 to 4 cents per share in each of the next three years.In premarket trading, King shares soared to $14.12, up 39 percent from Monday’s close. Pfizer shares dipped 8 cents to $17.30 – Timesofindia