Standard & Poor's

has affirmed its A-plus credit rating for

Bristol-Myers Squibb

(BMY) - Get Report

thanks to a favorable court ruling last week regarding the company's best-selling drug Plavix.

However, S&P also reaffirmed a negative outlook. S&P had placed the credit rating under review on Aug. 8 after Canada's

Apotex

launched

a generic version of Plavix, an anticoagulant that Bristol-Myers licenses for marketing in the U.S. from

Sanofi-Aventis

(SNY) - Get Report

.

Last week, a federal judge

issued an injunction that prohibits Apotex from making and shipping the product until a patent-infringement suit filed by the Plavix makers is decided. The case is scheduled to go to trial in January.

The judge refused a request from Bristol-Myers and Sanofi that he order a recall of the generic Plavix that had already been shipped to wholesalers. Apotex asked the judge to postpone the injunction, but he declined. Apotex says it will appeal the decision.

"We believe that the recent granting of the injunction is a positive development regarding Bristol-Myers' chances of prevailing in the patent trial, as the judge would not have granted the injunction if he believed that the company did not have a compelling argument," said S&P credit analyst Arthur Wong. "Still, as with any patent dispute, there is a high degree of uncertainty."