Teva Pharmaceutical said it will buy its partner Kowa’s 50 percent interest in their generics joint venture for $150 million, giving the Israeli drugmaker total control of Teva-Kowa Pharm.

The former joint venture will operate as a member of the Teva Group. The move gives the Israel generics powerhouse a stronger platform to take advantage of Japan’s generics market, a market expected to grow rapidly with the government push to increase the use of generics as a means to control the rising healthcare costs of an aging population.

Teva and Kowa established their joint venture in September 2008, and have since grown it into one of the top five generic players in Japan with sales of approximately $200 million in 2010. The buyout followed Teva’s completion in July of its acquisition of Taiyo Pharmaceutical Industry for $934 million.

Taiyo is Japan’s third largest generic pharmaceuticals manufacturer with sales of approximately $530 million in 2010. That deal gave Teva a portfolio of more than 550 products, access to all major Japanese pharmaceutical distribution channels, and a strong local R&D team with regulatory expertise and a state of the art production facility.

“Full ownership of all our activities including Taiyo will allow us to better grow our business in Japan,” says Shlomo Yanai, president and CEO of Teva. “With this stronger platform, Teva will be in a better position to further drive penetration of high quality generic pharmaceuticals in Japan and make better healthcare accessible to the Japanese people.”

Teva says it expects its combined Japanese operations will generate annual sales in excess of $800 million. Teva is the world’s largest generic drug maker with a market cap of $31.4 billion. It reported net sales of $16.1 billion in 2010. At the same time, Teva has been growing its branded drug business, having made significant investments in the past few weeks in cancer therapeutics startup CureTech and antiviral drug developer Cocrystal Discovery.

Teva is also in the process of acquiring Cephalon, a U.S.-based drug developer, for $6.8 billion.