Eric R. Greenleaf, 81, a retired chief engineer for the Chesapeake and Potomac Telephone Co. of Maryland and a speedboat racing expert, died of pneumonia Dec. 19 at Easton Memorial Hospital in Easton, Md.

Mr. Greenleaf joined C&P in Washington in 1921. He worked in a number of engineering positions before being named chief engineer, for the Maryland company in 1951. He retired in 1963.

During the 1940s, Mr. Greenleaf served for five years as chairman of the President's Cup Regatta Race Committee for power and was appointed general chairman of the regatta in 1949. He previously had served as general chairman in 1930. He was a former secretary of the Racing Committee of the American Power Boat Association.

Mr. Greenleaf lived in Trappe, Md. He was born in Orange, N.J., and earned a bachelor's degree in chemical engineering from Lehigh University in Pennsylvania. He was a veteran of World War I.

He was a life member of the Maryland chapter of the Telephone Pioneers of America and of the Washington Society of Engineers and was a former secretary of the Isaac Walton League of Washington.

Survivors include his wife, the former Betty Harrison, of Trappe; a daughter, Ellen G. McCarthy of Lynchburg, Va.; a son, Ethan A., of Baltimore, and three grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the American Heart Association.