A federal judge has upheld the patent on Bristol-Myers Squibb’s blockbuster blood-thinning drug Plavix, giving a huge victory to the pharmaceutical company.

Shares of Bristol-Myers had been roiled after a deal intended to keep a generic version off the market collapsed. But Judge Sidney H. Stein of the federal district court in Manhattan, found that the company that has sought to produce a generic, Apotex of Canada, had failed to prove that the patent on Plavix was invalid "on any of the grounds asserted."

Shares of Bristol jumped more than 4 percent in late morning trading. 

Bristol markets Plavix with Sanofi-Aventis of France, which is the maker of the drug and holds the patent until 2011. The drug had more than $6 billion sales last year. Apotex has been challenging the patent since 2003.

Bristol and Sanofi "are entitled to permanent injunctive relief and, as shall be determined by the court in a future proceeding, damages," the judge wrote.