Brian Thomas Moran, 51, who retired from the Central Intelligence Agency in 1977 after 26 years of service and them became a real estate agent in Montgomery County, died Dec. 9 at Montgomery General Hospital in Olney. He was hospitilized Oct. 30 after a stroke.

Mr. Moran was born in Fort Worth, Tex. He served in the Army during World War II, became a soldier in the 11th Airborne Division, and was assigned to Japan during the occupation there. When he left the Army, he returned to Texas and graduated from Texas A&M University.

He joined the CIA in 1951. His overseas assignments included Korea, Japan, Pakistan, Afghanistan, Turkey and Vietnam in addition to several years at CIA headquarters here. He established his home in Rockville in 1958 and lived there until his death.

After his retirement, Mr. Moran joined the Jack Foley real estate firm, which has offices in Silver Spring and Bethesda. He worked there until his illness.

He was a member of St. Patrick's Catholic Church in Rockville and of the Manor Country Club.

Survivors include his wife, the former Patricia A. Lynch, of Rockville; three sons, John S., of Silver Spring, Mark K., a student at Salisbury State College in Salisbury, Md., and Matthew B., of Rockville, and one daughter, Andrea K., of Rockville, a student at Montgomery College.