WASHINGTON (AP) _ The Supreme Court today refused to revive a lawsuit stemming from one of the nation's most publicized cases of alleged child abuse, at the now-defunct McMartin Preschool in Manhattan Beach, Calif.

The court, without comment, let stand a ruling that threw out the suit against a private child welfare group and one of its therapists by two of the preschool's former teachers.

Seven people connected to the preschool were indicted in 1984 on child- molesting charges, but charges against five later were dropped.

The two remaining defendants, Raymond Buckey and his mother, Peggy McMartin Buckey, were acquitted of most of the charges Jan. 18 after a three-year trial.

Jurors deadlocked on some of the charges, and prosecutors in Los Angeles plan to retry Buckey on some of those counts.

The appeal acted on today stems from a lawsuit by Buckey's grandmother, Virginia McMartin, and his sister, Peggy Ann Buckey. The women were among the defendants against whom criminal charges were dropped.

They said their rights were violated by the Children's Institute International and Kathleen MacFarlane, head of that organization's diagnostic unit.

The institute was hired by Los Angeles County and Manhattan Beach officials to help investigate the child-abuse allegations. The child welfare organization concluded that numerous acts of child abuse had occurred at the school.

In their suit, the two former teachers alleged that Ms. McFarlane leaked confidential information about the case to a television news reporter with whom she was involved romantically. The teachers also said the institute manipulated children attending the preschool to support the abuse charges.

A California appeals court last year threw out the suit, saying the institute and its employees cannot be sued because California law requires child care custodians and others to report to authorities any known or suspected instance of child abuse.

''Those subject to this mandatory reporting requirement are absolutely immune from civil or criminal liability for making such a report,'' the state court said.

Lawyers for the two teachers said such protection unfairly goes beyond even that accorded prosecutors.

''If the prosecutor ballyhooing his prosecution before the media is not absolutely immune for that performance, how can one say that Kathleen MacFarlane's pillow-talk leaks of inside information ... is entitled to absolute protection?'' they asked.

The case is McMartin vs. Children's Institute International, 89-1257.