James R. Sharp, 76, a lawyer in Washington for more than 40 years, died at George Washington University Hospital on Jan. 17 of a heart ailment and complications of diabetes.

Mr. Sharp came to the Washington area in 1942 and went into a private law practice shortly after World War II. He specialized in probate, trust, tax matters, international law and corporate law.

He was born in Hammond, Ind., and graduated from the University of Chicago and its law school. In 1934 and 1935 he was a special agent with the FBI. Later he worked for the old Bureau of Internal Revenue and the Securities and Exchange Commission. During World War II he was chief of the Foreign Agents Registration Section of the Department of Justice.

A resident of Arlington, Mr. Sharp was an enthusiastic gardener and an expert in the cultivation of azaleas and rhododendrons. He was a member of the Washington Golf and Country Club and the Little Falls Presbyterian Church in Arlington, which he helped organize.

His first wife, Emily Lowery Sharp, died in 1977. He is survived by his wife, Georgiana Sheldon Sharp, of Arlington; three children by his first marriage, Mrs. Richard Lombardi of Alameda, Calif., Mrs. Gary Swift of Arlington, and James L. Sharp of Wayzata, Minn., and nine grandchildren.