William Michalson, 79, a retired film sales representative and theater manager in this area, died Wednesday at his home in College Park after an apparent heart attack.

Associated with show business for more than 60 years, he had served as a publicity agent on nationwide tours of many of the movie greats.

Born in Chicago, Mr. Michalson ran a candy concession in a theater there as a teen-ager, and went on to manage theaters in New York and Philadelphia.

He also served as a troubleshooter for the William Fox theater organization in New York.

In the 1930s, he produced entertainment for prisoners at Sing Sing with the support of then warden Lewis Lawes.

Mr. Michalson came to Washington in 1944 for the 20th Century-Fox Film Corp. to arrange publicity for the premier of a firm, "Wilson," and remained as the corporation's publicity chief in this area for a number of years.

He also directed publicity for several major David Selznick productions here in the 1940s and 1950s. He was sales representative for American International Pictures until retiring in 1974. He continued to manage area theaters until last year.

He is survived by his wife, Ethel Horwitz Michalson, of the home; a daughter, Lois Lanham, of Largo, and a grandchild.