George Klebnikov, 73, a pioneer of simultaneous language interpretation. A native of Poland who grew up in France, Klebnikov spoke German, Russian and French. He worked as an interpreter during the war crimes trial at Nuremberg, the first case in which simultaneous interpretation replaced the older and slower method of translating. In 1946, he was hired as an interpreter and translator for the newly formed United Nations. He became head of its Interpretation Service in 1973 and retired 10 years later. On Tuesday in New York of complications from a stroke.