Leonard M. Berke, 81, of Potomac, a retired Justice Department economist, died June 10 of a stroke at Suburban Hospital in Bethesda.

Mr. Berke retired in 1980 as a senior economist after a 32-year career during which he was involved in major oil, rail and industrial mergers and antitrust cases.

Mr. Berke was born and raised on Manhattan's Lower East Side. He received a bachelor's degree in economics from Brooklyn College in 1940 and a master's degree in government and economic policy from George Washington University in 1948.

He worked briefly in 1942 in the Office of Price Administration in Washington and then enlisted in the Army Air Forces in 1943, serving for three years on his way to becoming a colonel in the Air Force Reserve.

After World War II, he returned to the OPA and then joined the Justice Department in 1948. In 1946, he married the former Ruth Kobre of Washington, whom he met in the reference room of the Library of Congress, where he was performing research of some kind while still in uniform, and she was studying for college finals.

He had been president of the Reserve Officers Association of Washington, the National Capital Association of B'nai B'rith and the John F. Kennedy Lodge of B'nai B'rith in Washington, and he and his wife were founding members of Congregation Beth-El of Montgomery County.

He is survived by his wife; three children, Richard Berke and Allison McCall, both of Washington, and Jennifer Levin Berke of Philadelphia; and four grandchildren.