The Food and Drug Administration rejected Merck & Co.'s request to market a successor to its withdrawn arthritis drug Vioxx in the United States, the drugmaker said Friday.

The move was widely expected, after a panel of FDA advisers two weeks ago voted 20-1 against approving the drug, Arcoxia.

Arcoxia is in the same class of drugs as Vioxx, which has become a poster child for drug safety problems.

Merck pulled Vioxx from the market in September 2004 after research showed it doubles risk of heart attacks and strokes. That triggered an avalanche of lawsuits — more than 27,000 so far — and a nosedive for Merck's stock price, which has since bounced back.

Despite the safety concerns in the United States, Arcoxia is on sale in 63 other countries, and Merck officials said as recently as Tuesday that they intend to keep working to get it on the U.S. market.

Arcoxia had been poised for approval until Vioxx was pulled from the market. Two months later, the FDA issued what's called an "approvable" letter, saying it could approve Arcoxia, but only if Merck provided further safety and efficacy information for the drug.

Merck has since produced results from further studies of Arcoxia, but doctors questioned those results because Merck compared Arcoxia in its tests to another painkiller that has elevated risk of heart attacks and strokes.

Peter S. Kim, president of Merck Research Laboratories, told company shareholders at their annual meeting Tuesday that "there is more long-term safety data on Arcoxia than" other drugs in the same class and traditional anti-inflammatory medicines.

"We are committed to working with the FDA to determine the best approach" to get it on the U.S. market, Kim said.

A Merck spokeswoman did not immediately return a call seeking comment Friday morning.

Merck shares sank 55 cents, or 1 percent, to $51.88 in morning trading on the New York Stock Exchange. They are still trading near their 52-week high of $52.63. Their low over the past year was $32.75.