William C. Stuart III, 86, a co-founder of Stuart & Maury Realtors in Washington, died Dec.­ 7 of cardiac arrest at the Rockville Nursing Home. A son, William C. Stuart IV, confirmed his death.

Mr. Stuart began his career in Washington in 1948 with Boss & Phelps, a development company. In 1956, he and two partners, Deane Maury and Charles “Ted” Berry, founded Stuart & Maury, which focused primarily on residential real estate.

According to his family and news accounts, Mr. Stuart sold a house in the 1950s to then-Vice President Richard M. Nixon.

Mr. Stuart retired in 2010.

William Clarkson Stuart III was born in Newport News, Va., and graduated from the old Augusta Military Academy in Fort Defiance, Va.

He was a past president of the D.C. Association of Realtors and received the association’s 1974 Realtor of the Year award. He served as a director of the National Association of Realtors and the Greater Washington Board of Trade and was a member of the executive committee of Downtown Progress, a business group. He also was a member of the Omega Tau Rho national real estate fraternity.

Mr. Stuart lived in Bethesda, the District and Annapolis before moving to Leisure World in Silver Spring. He was a member of the Episcopal Christ Church of Georgetown and the Chevy Chase Club.

Survivors include his wife of 62 years, the former Patricia Polk Morgan, of Silver Spring; four children, William C. Stuart IV of Washington, Alice S. Brenneman of Scottsdale, Ariz., Patricia S. Connor of Bethesda and Henry M. Stuart of Potomac; nine grandchildren; and four great-grandchildren.

— Matt Schudel