WHITEHOUSE STATION, N.J.--(BUSINESS WIRE)--Merck & Co., Inc. will hold its first-quarter 2009 sales and earnings conference call with institutional investors and analysts beginning at 8:30 a.m. EST on Tuesday, April 21. During the call, Richard T. Clark, chairman, president and chief executive officer, Peter N. Kellogg, executive vice president and chief financial officer, and Kenneth C. Frazier, executive vice president and president, Global Human Health, will provide an overview of Merck’s financial performance for the quarter.