Top executives at pharmaceutical giant Merck & Co. Inc. decided in May 2000 against developing a study to test directly whether its Vioxx painkiller drug might pose a heart risk, The New York Times reported on Saturday.

Just two months after results from a clinical trial suggested concerns the popular anti-arthritis drug might cause a higher risk of heart attacks, company scientists questioned whether a focused trial was possible and marketing executives apparently feared one would undermine sales, the Times reported in an article on its Web site.

Merck recalled Vioxx on Sept. 30 this year after a separate long-term clinical trial already under way in 2000 showed it doubled the risk of heart attack and strokes in patients who had taken it for over 18 months to prevent recurrence of colon polyps. Merck’s stock has fallen almost 38 percent since.

According to the Times report, based on what it called a detailed reconstruction of Merck’s handling of Vioxx, Merck scientists wondered in May 2000 whether a study to determine Vioxx’s cardiovascular risks, which might have required as many as 50,000 patients, was even possible.

The Times reported that a slide prepared for a meeting of top executives said: “At present, there is no compelling marketing need for such a study. Data would not be available during the critical period. The implied message is not favorable.”

The report is to appear in the Times’ Sunday edition.

Merck executives said this week the company acted responsibly, voluntarily withdrawing Vioxx as soon as it had clear evidence the drug was harmful. They said that even if they had conducted the type of study they discussed internally and rejected in 2000, the company might not have detected Vioxx’s risks any sooner.

“Merck wasn’t dragging its feet,” said Kenneth C. Frazier, the company’s general counsel. “It’s pretty hard for me to imagine that you could have done this more quickly than we did.”

The U.S. Food and Drug Administration, which Merck consulted, also agreed that designing a trial to specifically assess Vioxx’s cardiovascular risks would have been difficult and, unless constructed to provide benefits to patients, would have been unethical as well, the paper said.

The FDA recently published a study estimating Vioxx could have caused about 28,000 heart attacks or deaths since it was approved in 1999. An estimated 20 million Americans have taken Vioxx.