The trial of a Lebanese man accused in the 1985 TWA jet hijacking in which a U.S. Navy diver was killed opened Tuesday in a $6.6 million high-security courtroom and is expected to last a year.

U.S. officials will closely follow the trial of Mohammad Ali Hamadi, suspected of helping to stage the June 14, 1985, hijacking of TWA Flight 847 carrying 153 passengers and crew, mostly Americans, from Athens to Rome. The hijacking, lasting 17 days, is the longest on record.The trial opened 15 minutes late at 9:30 a.m. in a specially built courtroom on the grounds of Frankfurt's Preungesheim prison.

Proceedings immediately bogged down in a dispute over the Arab interpreter, who the defendant claimed was biased. Judge Heiner Mueckenberger said the interpreter, Egyptian national Fayek Riad, would remain on the job.

During the morning session, the court recessed twice to settle the dispute over the interpreter. A third break was ordered to allow Hamadi, dressed in a pale green prison shirt and blue trousers, to take some aspirin after he complained of a headache.

The slain diver's parents, Richard and Patricia Stethem, sat facing Ha-madi during the stop-and-start proceedings. Their attorney said they were weary of the delays.

Bulletproof glass separates the lawyers, the five-judge panel and the defendant from the press and visitors' section in the heavily guarded courtroom. About 100 reporters were frisked twice and guards even took apart their pens before allowing them into the courtroom.

"Mohammad Hamadi has become a Shiite (oslem) folk hero, so we are alert to everything," a court spokesman said about possible attempts to free the defendant.

Officials said the initial stages of the trial will be spent establishing Hamadi's age and reading charges. The trial could take a year.