UPDATE 1-US appeals court won't rehear Norvasc patent ruling

(Adds background, detail and comment from Pfizer)

WASHINGTON, May 21 (Reuters) - A U.S. appeals court on Monday denied Pfizer Inc.'s (PFE.N: Quote, Profile, Research, Stock Buzz) bid to get the court to reconsider a decision favoring Canadian drugmaker Apotex Inc. in its efforts to launch a generic form of Pfizer's blockbuster blood-pressure drug, Norvasc.

The U.S. Court of Appeals for the Federal Circuit turned down Pfizer's request for a rehearing of a decision in March, in which it reversed a lower court patent decision that had favored Pfizer in its bid to block Apotex from selling a generic Norvasc.

A poll of appeals court judges "was requested, taken and failed," the court said. Three of the 12 judges dissented.

Pfizer issued a statement shortly afterwards saying it would "explore our options for further appeal."

"We are disappointed that the court has declined to rehear what we believe is an incorrect ruling that is inconsistent with court precedent ...," Pfizer said in its statement.

The earlier ruling by the appeals court reversed a decision made by the U.S. District Court for the Northern District of Illinois.

The appeals court said the lower court erred when it found the discovery process for the patent was a unique process undertaken by Pfizer.