William G. Murphy, 57, assistant to the director of the Board of Contract Appeals of the General Services Administration, where he had worked for 16 years, died Jan. 5 at his home in Potomac after a heart attack.

Mr. Murphy was born in Washington. He graduated from Georgetown Preparatory School and Wabash College. He earned two law degrees at Catholic University.

During World War II, he served in the Army in Europe. He worked briefly as a civilian, then returned to active duty in Korea during the conflict there. He received the Purple Heart.

Mr. Murphy joined the staff of Rep. Hugh D. Scott (R-Pa.) in 1952. He became Scott's administrative assistant when Scott was elected to the Senate in 1958.

Mr. Murphy was an aide to former Pennsylvania Gov. William W. Scranton, and had worked in the presidential campaigns of Gov. George Romney and Richard M. Nixon before joining the GSA in 1969.

He was a member of Federal Bar Association and was a board member of the Potomac Glen Citizens Association.

Survivors include his wife of 34 years, the former Esther Winningham of Potomac; four children, Laurie Murphy of Woodbine, Md., Holly A. Murphy of Austin, Tex., Maureen Danforth of Reston, and William R., of Potomac, and his mother Maybelle Murphy of Pittsburgh.