VANCOUVER -- Inderjit Singh Reyat, the only person to be convicted in the Air-India disaster of 1985, testified yesterday in a calm voice about acquiring items used in bombs to kill 331 people.

As victims' families and members of the Sikh community listened intently in a packed courtroom, Mr. Reyat did not link Ripudaman Singh Malik or Ajaib Singh Bagri, the two defendants in the Air-India trial, to the crash.

However, for those who have waited 18 years to hear from someone involved in the deadly plot, his testimony was a significant turning point in the case.

"For the first time, people can hear with their own ears that he helped make the bomb," said Rupinder Kaur Hayer Bains, the daughter of Tara Singh Hayer, who was a possible witness in the case but who was murdered before the trial began.

"For years, the Sikh community has been saying people are being framed," she said in a brief interview outside the courtroom. "But it won't wash any more. People are hearing what he is saying."

Mr. Malik and Mr. Bagri are charged with murder over the deaths of 329 people in a midair explosion aboard an Air-India flight on June 23,1985, and the deaths of two baggage handlers at Tokyo's Narita airport 54 minutes earlier. The trial began in April.

Mr. Reyat was convicted of manslaughter in 1991 for the two deaths in Japan, but he did not testify at that time. He pleaded guilty to manslaughter this year -- without a trial -- in the deaths on the Air-India flight.

As he entered the courtroom yesterday, Mr. Reyat nodded to Mr. Malik in the prisoner's box. Mr. Malik appeared indifferent to the testimony, reading from a Punjabi-language prayer book and not looking at Mr. Reyat.

Wearing a blue turban, drab green windbreaker, jeans and runners, the 51-year old auto mechanic who has been in custody for 15 years often hesitated before responding to many questions about his activities in the 1980s, remaining silent for several uncomfortable seconds. Then he would say he does not remember.

He also told the court he could not recall any specific information from numerous telephone conversations between him and key suspects in the crime that were tape-recorded by Canada's spy agency and erased before the RCMP could review them.

However, he admitted playing a role in the deadly plot. Mr. Reyat told the court he bought two clocks that were used as bomb timers. He said he gave them to a man who had stayed at his house for almost a week, but he could not name him.

Mr. Reyat said he called the man Bhaiji -- brother in Punjabi. The prosecution says the unidentified man, Mr. X as they call him, built the bombs.

Mr. Reyat said Talwinder Singh Parmar, a radical Sikh in Vancouver, asked him in early 1984 to make a bomb that would explode in India, to help the Sikh people being mistreated by the Indian government.

Mr. Reyat said he believed the bomb would be used to blow up a bridge in India and he would not have acquired items for it if he had known people would be harmed.

In early June, 1985, he built a bomb of gunpowder placed inside a cardboard toilet-paper roll and exploded it in the bush on Vancouver Island, he testified. But Mr. Parmar thought the bomb was "useless."

After that, he acquired the clocks that he gave to the man whose name he never discovered, he said. He also helped pay for a tuner the unidentified man used to store one of the bombs, he said.

Geoffrey Gaul, spokesman for the prosecution, said outside the courtroom it is premature to assess Mr. Reyat's evidence because it "has only just begun."

And it is too early to consider whether the Crown may attempt to have Mr. Reyat declared a hostile witness, giving Crown prosecutors more latitude to question him aggressively, Mr. Gaul added.

Outside the courtroom, spectators -- many with connections to the Air-India case -- expressed skepticism that Mr. Reyat did not know the identify of Mr. X. "He knows exactly who Mr. X is," Ms. Bains said.

Surdip Kalsi, who said his sister was on Air-India Flight 182, told reporters that he believes Mr. Reyat "knows everything" about the terrorist plot.

"How can someone stay with you for four or five days, go shopping and everything and not know his name?"