David L. Black, a specialist in Latin American and Caribbean international and agricultural affairs and a former official with the Organization of American States, died June 12 at his home in Santiago, Chile. He was 79.

The cause was congestive heart failure, said his son David R. Black. The elder Mr. Black lived in Washington for decades and maintained a residence in the District even after moving to Miami and later, Chile, starting in 1997.

He worked for the OAS from 1980 to 1996, for several years as adviser for external relations to the secretary-general. He subsequently was chief of mission and representative to the United States for the OAS Inter-American Institute for Cooperation on Agriculture.

He helped develop and secure funding for many agriculture-related programs. He also was president and chief executive of the OAS Staff Federal Credit Union.

Mr. Black’s later career included consulting work in agriculture and agribusiness as well as trade and international relations work for the City of Miami.

David Luther Black was a native of Plainview, Tex., and was a 1954 graduate of Baylor University. He spent his early career at the Southwest Research Institute, a large nonprofit research center in San Antonio, where he became assistant to the president and helped secure funding for programs in nuclear energy and other fields.

He received awards for his contributions to international agricultural and technology programs from the U.S. Department of Agriculture and other organizations.

His marriages to Julia Williams and Susana Soler ended in divorce. Survivors include his wife of 29 years, Gloria Loyola-Black of Santiago; a son from his first marriage, David R. Black of Birmingham, Ala.; five stepchildren, Barry Snell and J. Whitfield Snell, both of San Antonio, Mario Ignacio Artaza of Hong Kong, Maria Francisca Artaza of Santiago and Paz Artaza-Regan of Kensington; and five grandchildren.

Adam Bernstein