Brazil's top appeals court has ruled that the patent on Viagra expires next month in the South American nation, a year earlier than argued by the manufacturer.
That means other companies can begin making generic versions of the erectile dysfunction drug in June. Pfizer Inc., which holds the patent, contends its patent runs until June 2011.
The court's ruling Wednesday says Pfizer registered its first patent in June 1990, so the 20-year term ends this year. Pfizer contends the patent was not finalized by the European Union until June 1991.
Pfizer says it sold $96.5 million worth of Viagra in Brazil last year. That was its third-biggest market after the U.S. and Britain.