Mumbai: Swiss drugmaker Roche Holding AG has sought legal action against Israel''s Teva Pharmaceutical Industries Ltd to prevent it from selling a generic version of Roche''s osteoporosis drug Boniva in the United States.

"We have filed a complaint for patent infringement in the New Jersey court against Teva," Roche said.

"Their products infringe on Roche''s patent rights," Roche spokeswoman Martina Rupp said.

Boniva, which is sold as Bonviva in Europe, is covered by patents running from 2012 to 2023. "Our product is not off patent yet," she said.

Sales of Boniva for the first six months of the year totaled 372 million Swiss francs ($314 million; €228 million).

Bonviva belongs to a class of drugs known as bisphosphonates. The total market for that class of drugs is worth an estimated 1.4 billion euros and is expected to grow to 3 billion euros by 2010.

Roche''s domestic rival Novartis AG and Teva have been involved in patent infringement litigation since 2005.

Novartis, meanwhile, said a US court halted Teva''s sale of a generic version of its Famvir herpes treatment. The injunction by the US Court of Appeals for the Federal Circuit was issued on Friday, two days after a district court in New Jersey denied a motion to stop Israel''s Teva from marketing its version of the drug, Novartis said.

The injunction requires Teva to submit a response by September 11, Novartis said. Novartis said earlier this month it would take a one-off charge worth up to $300 million for impairment of intangible assets after Teva launched a generic version of its antiviral compound Famvir, a herpes treatment.