As Administration negotiators near a trade agreement with Japan on computer chips, Sematech officials said today that American chip makers faced long delays, or higher prices, in trying to buy advanced equipment from five Japanese companies.

Administration negotiators say they were convinced that if forced to accept productivity gains, the unions would have balked and opted for binding arbitration that might not favor the city.

House and Senate leaders from both parties are scheduled to meet Tuesday on Capitol Hill with Administration negotiators to see if they can find a way to compromise.

Administration negotiators complained that the system of international spot checks on biological research centers favored by most other countries would not stop secret violations of the treaty.

The Administration negotiators reopened the issue, leading the Congressional side to suspect they were trying to back away from an agreement to reduce military spending by about $5 billion in 1988 below the 1987 level, plus an increase for inflation.

The Administration negotiators also presented their latest economic forecast, which included more pessimistic assumptions about interest rates, inflation and economic growth.

Administration negotiators have had to walk a narrow path in making concessions to lawmakers while not altering any of the concessions made to Canada under the pact, which represents a balance of concessions by both sides.

In discussions over the last month, Senate leaders and Administration negotiators have reached agreement on many elements of legislation to strengthen the Clean Air Act of 1970.

Here again, Administration negotiators have been working to line up support, and Mr. Clinton has telephoned undecided Senators.

Furious Democratic leaders, noting that they had exchanged a series of budget offers with Administration negotiators over the last 24 hours, quickly moved to counter Mr. Bush's charges and hurl some of their own.