The U.S. military command in Europe in 1948 barred immigrant American Jews, steeped in German language and culture, from further participation in the allied hunt for World War II Nazi sympathizers, according to a secret U.S. memorandum acquired by Holocaust researchers.

The memo, made available to the Simon Wiesenthal Center here by an Austrian-born American who was a postwar Army investigator, "in effect eliminated some of our best intelligence operatives from key posts in Europe . . . even as criminals like Klaus Barbie were going onto our intelligence payrolls," said Rabbi Abraham Cooper, the center's associate dean.

Cooper said he has asked House Judiciary Committee Chairman Peter W. Rodino Jr. (D-N.J.) to investigate the hitherto unreported postwar policy. He said it sheds new light on the recent conclusion by the congressional General Accounting Office that many Nazi collaborators escaped detection because U.S. investigators "were inexperienced and lacked necessary skills."

Labeled "civilian personnel memorandum no. 21" and dated March 22, 1948, the document said that any American civilians henceforth hired as intelligence agents, criminal investigators or other "sensitive" positions "will be required to have had a minimum of 10 years U.S. citizenship."

Walter R. Bass, 73, a retired fashion designer living here, said he recently came upon the memo in his files and turned it over to Cooper. No other official from the period could be reached to confirm its authenticity. He said the policy appeared to have been aimed at many Jews who, like himself, immigrated from Europe to escape Hitler in the late 1930s and returned as U.S. citizens to fight in the war, then helped in de-Nazification when the war ended in 1945.

"We thought it was very unjust," Bass said of the 1948 memo. His contract as a civilian investigator with the military government in Germany was not renewed because of the policy. There were no overt protests at the time, Bass said.

He noted that even he did not realize the severe consequences the policy might have had until he read recent reports of several Nazis wanted for war crimes reaching the United States and, like Barbie, even working with U.S. forces after the war.

The memo, signed by Lt. Gen. C.R. Huebner, based the policy on a requirement that "personnel who occupy intelligence, investigative and certain other sensitive positions be impartial and objective in their service, and above criticism as to their loyalty to the government of the United States."

Bass said he and others "who made sincere and strong efforts to produce a real de-Nazification encountered a lot of criticism and obstruction from other military government personnel." He said those who were "the most eager and sincere in their work . . . were called 'too gung-ho.' "

The problem, Bass said, was the emerging Cold War and "a competition between the Russians and ourselves for the hearts of the Germans." Whenever the Soviets exempted certain classes of former Nazis from postwar penalties in their sector of Germany, the Americans would try to follow suit, Bass said.