Hamburg - A German company is preparing to manufacture a copy of the erectile-dysfunction medicine Viagra as soon as the patent in Germany runs out, a business weekly reported Saturday.

The US company Pfizer has the German patent on Viagra until 2013. After that, any company can manufacture and sell the substance.

Ratiopharm, one of Germany's main makers of generic drugs, has already applied for approval from European drug safety authorities for its copycat product and was expecting a clearance by the end of this year, said the weekly Wirtschaftswoche.

Patent drugs are usually sold at enormous prices because of the monopoly granted to the maker. Generic medicines are far cheaper, because free competition between makers drives down both profit margins and manufacturing costs. (dpa)