But the Energy Department said yesterday the plant, operated by the Rockwell International Corporation, would not be shut down in the next few days.

A replacement for the Challenger is being built by the contractor, the Rockwell International Corporation, and should be delivered in 1991.

The Rockwell International Corporation said yesterday that it planned to buy back an additional $500 million of its common stock.

The biggest loser as a result of the cuts was the Rockwell International Corporation.

Sixty of the 400 scientists employed by the Pittsburgh-based Rockwell International Corporation are foreign.

The Rockwell International Corporation said today that its third-quarter earnings fell 3.9 percent on a 3.1 percent decline in revenues.

Intervoice, which makes computerized systems that respond to the human voice, signed a marketing agreement with the Rockwell International Corporation.

The Rockwell International Corporation said its board had extended the company's stock repurchase program by an additional $500 million.

Another big aerospace company, the Rockwell International Corporation, posted a decline in earnings.

But the agreement was not signed by the Rockwell International Corporation, which operates the plant for the Energy Department.