Retired Army Maj. Frederick O. Petite, 71, owner and operator of the Petite Realty Co. here since 1947, died Tuesday at his Washington home after a heart attack.

Maj. Petite was high school science teacher in Salisbury, Md., and worked for the old Reconstruction Finance Corporation and the old Department of the Post Office before establishing his real estate business.

A native of Washington, he graduated from Dunbar High School and from Howard University.

He was commissioned into the Army's Officer Reserve Corps in 1929 and served on active duty in this country from 1940 until 1946, when he retired because of a disability.

Maj. Petite was active in St. Mary's Episcopal Church here for more than 50 years and served as junior warden for the past 15 years.

He was a member of the board of admissions and the board of directors of the St. Mary's Court housing development for the elderly in Northwest Washington.

He also was a member of the 366th Veterans Organization and of the WBW and ACBL bridge organizations and the Aces & Bridge Masters Club.

Survivors include his wife, the former Annice C. Gray, of the home. CAPTION: Picture, FREDERICK O. PETITE