The American Broadcasting Co., which last week agreed to pay nearly $500,000 to a former employe who had filed a sexual harassment lawsuit against the network and one of its former vice presidents, now is trying to win legal sanctions against whoever disclosed the supposedly secret amount of the settlement.

The network agreed last Tuesday to make the payment to Cecily Coleman, the former executive director of ABC's voter education program, but under terms of the agreement did not reveal the amount of the settlement.

However, The Washington Post, citing "other sources," published the amount of the settlement in last Wednesday's editions. Stuart Gerson, a lawyer for ABC, immediately asked U.S. District Judge Barrington D. Parker to impose the sanctions.

Judges can impose sanctions -- a form of punishment, such as holding lawyers and others in contempt of court or fining them -- if they violate court orders. In the past, Parker has fined lawyers from $100 to $300 for offenses such as being tardy in filing court papers.

The judge said in court last week that the terms of the settlement would be announced only to the extent of the joint statement issued by ABC, Coleman and the man she accused of sexually harassing her, James D. Abernathy, ABC's former vice president for corporate affairs. Yesterday, Parker issued a written order saying that the network, Abernathy, Coleman, their lawyers and spouses were to keep the terms of the settlement "strictly confidential."

Gerson, in an effort to find who leaked the information without disclosing further details of the case, asked Parker, and the judge agreed last Wednesday and again yesterday, to lock the courtroom to the public while Gerson questioned several witnesses about the leaked information.

Gerson said yesterday that the courtroom should be closed because the testimony could relate to the terms of the settlement. Lawyers for Coleman and the National Organization for Women's Legal Defense and Education Fund, which assisted her in the case, did not object to closing the hearing. Parker, over the objections of a Washington Post reporter, ordered the Post reporter and one for the Associated Press to leave the courtroom.

Gerson last Wednesday questioned Coleman and her husband, James Prior, and yesterday asked Marsha Levick, a NOW Legal Defense lawyer, what she knew about the leaked damage settlement. The hearing is scheduled to continue this morning with questioning of Emily J. Spitzer, another NOW attorney.

Coleman's case against ABC and Abernathy was scheduled to go to trial last week, but was settled after 48 hours of what Parker called "serious and intense" negotiations. At the time, ABC said the settlement "marks an amicable conclusion of the case."

Coleman contended in her lawsuit that Abernathy, her boss, had made repeated physical and verbal advances and "told her she could enjoy a promising future 'if she played her cards right.' " Coleman was later fired after she complained about the allegations.

Both Abernathy and ABC denied all the charges.