Roland Haddaway del Mar, 73, a retired Army major general who was active in Latin American affairs, died Tuesday at George Washington University Hospital after a heart attack.

Gen. del Mar, who lived in Washington, was born in Attica, Ind., and grew up in Winnetka, Ill. He graduated from the College of Wooster in Ohio and was commissioned in the horse cavalry of the Army Reserves in 1931. Before World War II, he worked for the International Harvester Co. in Ohio and Indiana.

Called to active duty in World War II, he served in the Pacific during the war and in the occupation of Japan afterwards. He served in Korea during the conflict there. He also served in Germany, Italy and Puerto Rico. He was director of the Inter-American Defense College at Fort Leslie J. McNair in Washington at the time he retired in 1966.

Gen. del Mar's military decorations included the Distinguished Service Medal, the Legion of Merit and the Bronze Star.

When he left the military, the general became the administrator of the Charles del Mar Foundation, a philanthropic organization started by his father. He also was chairman of the Maryland Commission for Latin American Affairs, a consultant to the Pan American Development Foundation and president of the Americas Foundation in New York.

He was a trustee of the College of Wooster, a director of the International Club, a director of the Washington International Horse Show and a member of the Chevalier du Tastevin and the Army & Navy Club.

Survivors include his wife, Elizabeth Adams del Mar of Washington; a daughter, Mareen Braddock of Alexandria, and a grandchild.

The family suggests that expressions of sympathy be in the form of contributions to the Army Distaff Hall, Washington, D.C. With art