June 12 (Bloomberg) -- Sanofi-Aventis SA, France's largest drugmaker, sued Indian rival Sun Pharmaceutical Industries Ltd., alleging infringement of a U.S. patent for Uroxatral, used to treat an enlarged prostate gland.

Sanofi asked a judge to prohibit Sun from marketing a low- cost generic version of the drug until the patent expires in 2011, according to a complaint filed yesterday in federal court in Delaware.

``Plaintiffs do not have an adequate remedy at law'' and ``will be irreparably harmed'' by Sun's infringing activities without a judicial ruling, Sanofi lawyers said in court papers.

Sanofi, based in Paris, with about $38 billion in 2007 revenue, also sued closely held Apotex Inc. and subsidiaries of Teva Pharmaceutical Industries Ltd. and Barr Pharmaceuticals Inc. last year in the same court over generic versions of the medicine.

Nina Devlin, a Sun spokeswoman in New York, said the company doesn't comment on pending litigation.

Shares of Sun, India's largest drugmaker by market value, with about $833.3 million in sales last year, rose more than 4 percent June 2 after the company reported that quarterly profit more than tripled.

Sanofi-Aventis shares rose 11 cents to 42.99 euros in trading today in Paris. Sun, based in Mumbai, rose 32.25 Indian rupees to 1,476 rupees in trading in India.

The case is Sanofi-Aventis v. Sun Pharmaceutical Industries Ltd., 08CV350, U.S. District Court for the District of Delaware (Wilmington).

To see the patent, click 4,661,491.

To contact the reporter on this story: Phil Milford in Wilmington, Delaware, at pmilford@bloomberg.net.

Last Updated: June 12, 2008 13:25 EDT