Merck

(MRK) - Get Report

said Tuesday that its board appointed a special committee to examine the company's actions prior to the withdrawal of arthritis drug Vioxx from the market on Sept. 30.

The committee will speak for the board in shareholder litigation matters and recommend changes in corporate policy as warranted, the company said after markets had closed. Merck is expected to update its post-Vioxx financial guidance in

an analysts' meeting Wednesday.

Merck's behavior has already been placed under a microscope by Congress, the Justice Department and the

Securities and Exchange Commission

.

Board member William G. Bowen, president of the Andrew W. Mellon Foundation and chair of the Merck board's corporate governance committee, will be in charge of the special committee.

"Even though the FDA has noted that the company acted responsibly with respect to Vioxx, the board concluded that its responsibilities to Merck shareholders made it important to conduct an independent review in order to ensure that the company acted in an appropriate and ethical manner," Bowen said. Five other outside directors will serve on the special committee.

"The committee will have the complete cooperation of Merck management and the full resources it needs to conduct its assessment," said Raymond V. Gilmartin, chairman, president and CEO of Merck.

Merck's stock lost 23 cents, or 0.8%, to close at $27.89.