A sharp cut in funding will force the Department of Energy to curtail its effort to employ Russian nuclear scientists in civilian jobs and keep them from peddling their bomb-building talents to other countries, officials said yesterday.

The $7.5 million appropriated by Congress last month for the so-called Nuclear Cities Initiative in fiscal 2000 is half of what was allocated this year and a quarter of what the Energy Department requested. As a result, the administration will limit the program to scientists in one Russian nuclear city instead of three, said Rose E. Gottemoeller, director of the department's nonproliferation office.

The program began in September 1998 as a response to desperate economic conditions in Russia's "secret" cities, which during the Soviet era were ringed with security fences and did not appear on official maps but received special supplies of food and luxury goods.

Since the end of the Cold War, the special supplies have stopped, Russia's production of nuclear weapons has plummeted, and many nuclear workers have lost their jobs. The 17 facilities that make up the Russian nuclear weapons complex once built up to 4,000 warheads a year but now produce just 200 to 300, said Oleg Bukharin, a Princeton University expert.

Nevertheless, the complex still employs 100,000 professionals in seven former secret cities and around Moscow, about twice the number of facilities and four times as many nuclear weapons workers as in the United States, according to Bukharin.

Gottemoeller said the Energy Department will focus solely on the city of Sarov, formerly known as Arzamas-16, the Russian equivalent of Los Alamos.

The program's most publicized success was the opening last month of a computing center in Sarov that will produce software for sale around the world. It uses IBM computers that the Russians bought in 1996 and had begun using for nuclear weapons work in violation of U.S. export laws. Months of negotiation led to their removal from the weapons facility and their transfer to the open, commercial venture.

The budget cut by Congress stemmed primarily from a report by the General Accounting Office that said some U.S. funds appeared to be going to Russian scientists who were still working on weapons. In response, Congress inserted a provision in next year's nuclear cities appropriation that requires Energy Secretary Bill Richardson to certify that Russia has agreed to close some facilities engaged in nuclear weapons work.

Kenneth N. Luongo, a former Energy Department official who helped establish the program, said he found on a trip to Russia this fall that the directors of its nuclear facilities have come to support the U.S. employment effort, despite initial skepticism.

"If you give them a career, [Russian scientists] will loosen their grip on military programs," Luongo said, adding: "The opportunity is on the table now. It may not be there five years from now."

The nuclear cities program, however, is just one part of a wide-ranging, $1 billion U.S. government effort begun in 1991 to help Russia reduce its enormous nuclear arsenal and secure its stockpiles against theft.

The portions of the initiative run by the Pentagon and State Department, which account for more than half the total funding, also have been cut or reshaped by Congress this year. At the insistence of the House Armed Services Committee, $110 million requested to help pay for a plant to destroy Russian chemical weapons was eliminated, and the funds were redirected to destroying some of Moscow's strategic nuclear warheads under arms control agreements.