With just two sentences buried in a report, a Senate committee has revived the sticky debate over government purchases of foreign-made supercomputers.

The statement, tucked into a report accompanying the Senate energy and water appropriations bill, gives the Secretary of Energy authority to acquire a Japanese supercomputer for Lawrence Livermore National Laboratory in California, an action that would flaunt a long-standing unofficial government policy of buying only U.S. supercomputers.

By singling out the Japanese as a potential supplier, the bill has angered some on Capitol Hill who worry that such special treatment could further chip away at the competitiveness of U.S. computer makers.

"Our government should not be buying from the competition when we have a technological lead and we limit the ability" through export controls "of our own companies to exploit foreign markets," said Eileen Baumgartner, legislative director for Rep. Martin Sabo (D-Minn.).

For years U.S. firms have been the leading producers of supercomputers, the fast, number-crunching machines that can make highly sophisticated mathematical calculations and cost millions of dollars to purchase. But recently, some Japanese machines have been said to surpass the speed of American-made models, which only heightens the desire among supercomputer users to get their hands on a Japanese machine.

"Nobody we know has really evaluated a Japanese machine on a full-fledged workload," said Robert Borchers, associate director for computation at Livermore. "We're seriously trying to evaluate what's out there."

Borchers said he has his eye on a model built by Japanese computer maker NEC Corp. that is reported to be several times faster than the fastest model available today from Cray Research Inc., the leading U.S. supercomputer maker. No purchase negotiations are underway, however.

Bolstering Livermore's position is an agreement between the United States and Japan reached in March that declares each nation will open its supercomputer market to the other. But some people are concerned that Japanese computer makers are gaining more from the pact than are U.S. firms.

Even some in the Energy Department, which funds Livermore, claim to be perplexed by the apparent government approval of the purchase, especially when the NEC machine is still unproven. "The question is, 'Where does the U.S. government put its money?' ... and the last place is essentially completing a {Japanese} system," said Norman Kreisman, a department adviser on international technology.