William L. Strieter, 56, who was chief property manager in the overseas administrative support branch of ACTION, died Sunday at the Mount Vernon Hospital in Alexandria following a heart attack.

Mr. Strieter sold real estate in this area and was associated with the Thomas J. Fisher Co., Laurence Seigler Realty and the Hugh T. Peck commercial sales division in Wheaton before joining ACTION about 1973.

He was born in Washington and graduated from St. John's College High School here in 1940. He attended The Citadel military college in Charleston, S.C., before enlisting in the Army during World War II.

He earned a Purple Heart for wounds received while serving as a paratrooper with the 82nd Airborne Division in Holland and France.

After the war, Mr. Strieter returned to Washington and earned a bachelor's degree in business administration from George Washington University.

He was a member of the Redskin Alumni, the Home Plate and Touchdown clubs, the Jaycees and the Kiwanis International. He also was a member of the 82nd Airborne's 508 Club and was a life member of the Disabled American Veterans.

Survivors include his wife, the former Sharon Bloomgren, and a daughter, Danielle, of the home in Alexandria and three brothers, Louis S., of College Park, John D., of Silver Spring, and James D., of Edgewater, Md.

The family suggests that expressions of sympathy be in the form of contributions to the Heart Fund or to the Washington Area Tennis Patrons Association, 3300 Whitehaven St., Suite 501, Washington, 20007.