Mohammed Hamadi "gloated" after a U.S. Navy diver was slain during the hijacking of a TWA jetliner, an American witness testified Wednesday at Hamadi's trial on air piracy and murder charges.

Peter W. Hill was one of 39 Americans held hostage for 17 days aboard TWA Flight 847 after it was seized on a flight from Athens to Rome and diverted to Beirut.U.S. Navy diver Robert Stethem was shot and killed during the ordeal in June 1985.

Hill told the court that long after Stethem was killed, Hamadi started talking to him and another hostage on the plane.

"Hamadi, gloating, said `This is the gun that killed him (Stethem).' He seemed quite proud of it," said the 60-year-old Hill.

Hill said that was the only time he saw Hamadi with the gun in his hand.

Hamadi has admitted that he was one of the hijackers but denies killing Stethem and said he tried to prevent the slaying.

Hill, who lived in Hoffman Estates, Ill., at the time of the hijacking, was the first American to testify at Hamadi's trial, which resumed Tuesday after a four-week recess.

Hill worked as Midwest manager of a West German travel agency and was directing a Holy Land tour of a group of Chicago-area residents who were aboard the hijacked plane.

During testimony Tuesday, Hamadi repeated his claims of innocence involving Stehem's death, but he refused to identify the accomplice who he says shot the sailor.

"I already said the other (one of his accomplices) was responsible and he was the murderer," Hamadi said.

"Our orders were not to kill. We were told to hijack the plane, to force it to land and to state our demands. But not to kill," Hamadi said. He refused to say who issued the orders.