Jacques Joseph Reinstein, 91, an administrator at the State Department when he retired in 1971 after a 35-year career as a Foreign Service officer, died of cardiovascular disease Oct. 31 at the Chevy Chase House retirement facility in Washington.

He lived off and on in Washington since the late 1920s.

Mr. Reinstein, a native of Savannah, Ga., was a graduate of the School of Foreign Service at Georgetown University.

He worked for the National Reconstruction Administration in the 1930s before joining the State Department.

During World War II, he was an economics expert focused on the financial reconstruction of Europe. He was economic adviser to the U.S. delegation to the Paris Peace Conference in 1946.

In the late 1940s, he was an economist on the policy planning staff that developed the Marshall Plan.

He later was director of the Office of German Affairs, an economics affairs instructor at the Foreign Service Institute and coordinator of the Second United Nations Development Decade.

He received the State Department Distinguished Service Award in 1952.

After his retirement, he was a lecturer at George Washington University and was a member of the board of the Atlantic Council.

His marriage to Rachel duBois Campbell Reinstein ended in divorce.

Survivors include his wife, Floye King Reinstein of Washington, whom he married in 1982; three sons from his first marriage, Robert, of Rockville, John, of Brookline, Mass., and Stephen, of West Chester, Pa.; two stepchildren; 11 grandchildren; three great-grandchildren; and one great-great-granddaughter.