WHITEHOUSE STATION, N.J.--(BUSINESS WIRE)--Merck (NYSE: MRK), known as MSD outside the United States and Canada, today announced that Richard T. Clark, chairman, will retire from the company and the Merck board of directors effective Dec. 1, 2011. Clark led the company for five years as president and chief executive officer from 2005 through 2010. He has served as a Merck director since May 2005 and chairman of its board of directors since 2007. In January 2011, Kenneth C. Frazier became Merck’s president and chief executive officer and a member of its board. Today the board elected Frazier to serve as chairman following Clark’s retirement.
