AstraZeneca PLC said Monday it is exercising an option with Merck & Co to take back full rights to some of its drugs marketed in the United States and will pay the U.S. company $647 million.
The deal is part of the planned unwinding of trading agreements between the two companies that have given Merck royalties on the U.S. sales of several AstraZeneca medicines, including heart drugs Atacand and Plendil.
AstraZeneca said it expects the option to close in 2010.
A second option to repurchase Merck's interests in AstraZeneca's heartburn drug Nexium and its older product Prilosec is now exercisable in 2012 or 2017, or if the combined annual sales of the two products fall below a minimum amount.
The sales, marketing and distribution agreements for the United States were initially set up in 1982 when a joint venture was created. That was restructured in 1998 to form a U.S. limited partnership.