General Motors Corp. and the federal government agreed to a procedural step yesterday that could hasten the end of the auto maker's lengthy X-car trial here.

The two sides set a May 17 deadline for submitting remaining evidence to the U.S. District Court, effectively shutting off oral testimony that has kept the trial running -- albeit with frequent stops -- since it started up 14 months ago.

GM is accused in the case of marketing the front-wheel-drive, 1980-model X bodies with rear brakes that could lock in moderate-to-hard stops and cause loss of driver control.

The Department of Justice, on behalf of the National Highway Traffic Safety Administration, is asking the court to fine GM $4 million and to force the auto maker to recall "all" of the 1.1 million X cars manufactured for the 1980 model year. About 800,000 of those models still are on the road, according to GM and other auto industry officials.

In a related matter, the government is accusing GM of knowingly marketing the cars with a defect and of lying to cover up the problem. Ajudication of the second charge will depend on how the court rules on the first issue -- whether the 1980 X cars pose an unreasonable risk to the driving public.

GM contends that the cars in question are safe, and the company denies that it lied to try to conceal a defect. The company acknowledges that it is its corporate reputation -- not the $4 million or any recall expenses -- that has been put at risk in the case.

To bolster their arguments on the safety issue, both GM and the government have spent the past year introducing tens of thousands of pages of data and hundreds of technical exhibits. Expert witness after expert witness has mounted the stand in the paneled courtroom of U.S. District Judge Thomas P. Jackson, who is hearing the case without a jury.

It has not been a flashy affair. There have been no legal epiphanies, no obvious turn of events or introduction of evidence that would seem to favor one side over the other.