The U.S. Appeals Court here yesterday ruled that persons who file baseless lawsuits against the federal government alleging sex or race discrimination can then be billed by the government for the amount of money it spent defending itself against the charges.

The ruling, which affirmed a similar holding by a trial court judge two years ago, was the first appellate decision of its kind.

It could affect the number of such cases that are filled in federal court here charging job bias on the part of government cases said yesterday, by deterring persons from filing suits without strong evidence in their favor.

The appellate court, however, noted that the main effect of its ruling probably would be to "help to discourage those few suits whose only motivation is harassment."

"Litigation brought merely to harass is a wholly unredeemed burden and affront to the judiciary," U.S. Circuit Judge Malcolm Wilkey wrote for a unanimous three-judge court.

In the case, U.S. District Judge John H. Pratt had ruled at trial that Barbara Copeland, a black female federal employee, "abused the judicial process" by filing the suit against the Community Services Administration.

He said she brought the suit "in bad faith, with an intent to harass her supervisors and generally vex the defendant through her abusive conduct."

The suit appeared, Pratt said, to be part of a "vendetta" she was conducting against her supervisors.

He said, also, there was no "credible evidence" bias had anything to do with her failure to be promoted from a GS-11 program specialist to a GS-12 slot. In fact, Pratt said, her agency had a black employment of 80 percent, females outnumbered males by a ratio of 2 to 1, and her supervisor primarily promoted black females.

The appeals court said the facts were not disputed, but that the woman's attorneys argued only that the government never could win attorney's fees in a civil rights case.

At the time of the original ruling, government officials said they probably would bill the woman at the rate of $27 an hour - less than most attorneys charge, since the government does not include such items as overhead in its billing - for a total of about $4,000.

Neither Copeland nor her attorney could be reached for comment yesterday.