NEW YORK -(Dow Jones)- The U.S. Court of Appeals for the Federal Circuit won't alter a March decision blocking Teva Pharmaceutical Industries Ltd. (TEVA) from selling a generic version of Pfizer Inc.'s (PFE) blockbuster painkiller Celebrex for six years.

In March, the court threw out one of three patents on Celebrex, but backed a lower court decision that ruled Teva infringed on two others, which are valid until May 2014.

Following that decision, both companies filed petitions for rehearing certain parts of ruling. Both were denied on Tuesday, according to a court spokesperson.

Pfizer declined to comment on the development; Teva officials weren't immediately available.

A lower court ruled last year that Pfizer's multiple patents on the drug met the legal standard to preclude Teva from marketing a generic form of Celebrex.

Celebrex, with sales of $611 million for the first quarter, has been a strong product for Pfizer, which has a lack of promising late-stage candidates in its pipeline and faces both existing and looming generic competition for key drugs.

The company's biggest seller, the cholesterol drug Lipitor, brought in more than a quarter of its $11.85 billion in first-quarter revenue, but could see generic competition as early as 2010.

Pfizer shares recently fell 15 cents, or 0.7%, to $19.96; while Teva shares dropped $1.12, or 2.4%, to $45.59.

- Thomas Gryta; Dow Jones Newswires; 201-938-2053; thomas.gryta@dowjones.com

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  05-07-08 1214ET
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