our men were convicted yesterday of conspiring with Osama bin Laden in a terrorist plot to bomb the American Embassies in Kenya and Tanzania in 1998. The blasts killed 224 people, injured thousands and glaringly exposed the United States' vulnerability abroad.

Two of the defendants were also found guilty of murder and could now face execution. American prosecutors are seeking to impose the death penalty for the first time for terrorism committed against Americans in a foreign country.

The jury of seven women and five men returned the verdicts after about 12 days of deliberations in Federal District Court in Manhattan. The four defendants showed no visible emotion as the jury forewoman replied "guilty" over and over as the seemingly endless string of crimes listed in the 302-count indictment was read aloud, a process that took more than an hour. The verdict took so long to read that the judge, Leonard B. Sand, and a court clerk took turns reading from the verdict form.

Prosecutors are seeking the death penalty for two men — Mohamed Rashed Daoud al-'Owhali, 24, and Khalfan Khamis Mohamed, 27 — who were convicted of murder in the deaths of the victims in each bombing. Hearings, required under federal law, will be held separately for each man before the same jury, starting today, to determine whether they will be sentenced to death or life in prison without possibility of parole.

The third man — Mohammed Saddiq Odeh, 36 — was found guilty of aiding and abetting murder in the Nairobi, Kenya, bombing. He faces life in prison without parole. Prosecutors had decided earlier not to seek the death penalty in his case, without explaining why.

The fourth defendant, Wadih El- Hage, 40, also faces life without parole for his role in the terrorism conspiracy, although the government acknowledged that he had no role in the bombings.

The verdicts are a victory and a validation for the federal prosecutors in Manhattan, who offered the jury a detailed case over the last four months that placed the four defendants in a global conspiracy led by Mr. bin Laden and rooted in Islamic fundamentalism and a hatred of Americans.

"Today's guilty verdicts are a triumph for world justice and for world unity in combating international terrorism," said Mary Jo White, the United States attorney in Manhattan, adding that the government's work was not finished.

"We remain permanently and unrelentingly committed to tracking down, apprehending and bringing to justice every single participant in these crimes, however long it takes and wherever around the globe it is necessary to go," she said.

Barry W. Mawn, the assistant director in charge of the New York office of the F.B.I., noted that the bombings investigation represented the largest ever conducted abroad by the F.B.I., whose agents held thousands of interviews.

Over the course of the trial, which included about four months of testimony, prosecutors called 92 government witnesses and introduced more than 1,300 exhibits. These included Mr. El-Hage's grand jury testimony in 1997 and 1998, which prosecutors said included 96 false statements, and clothing belonging to Mr. Odeh on which traces of explosive residue were found.

None of the four defendants testified, but the lawyers for Mr. El-Hage and Mr. Odeh called witnesses and introduced exhibits trying to undermine the government's case. Mr. El- Hage's business partner testified, for example, while an Islamic religious leader testified on behalf of Mr. Odeh, whose lawyers told the jury that their client would not have violated Islamic law.

Lawyers for the two men who could face the death penalty, Mr. al- 'Owhali, a Saudi citizen, and Mr. Mohamed, a Tanzanian, refused to comment on the verdicts.

"It's premature to discuss anything," said David P. Baugh, a lawyer for Mr. al-'Owhali, whose death penalty hearing will be heard first and is to begin this morning. "We are still deep in this trial. We consider this to be the middle of the case."

But lawyers for the two other defendants said they would appeal the verdicts.

Anthony L. Ricco, one of the lawyers for Mr. Odeh, a Jordanian who helped in the preparations for the Nairobi bombing, said: "These were tough emotional charges. I thought that Mohammed had a real issue of reasonable doubt."

Another of his lawyers, Edward D. Wilford, added, "In our opening statements, we asked the jury to be courageous, but there was an emotional hype we could not overcome."

Lawyers for Mr. El-Hage, a naturalized American citizen from Lebanon who lived in Arlington, Tex., said the nature of the bombing had tended to overwhelm the defense they tried to mount on behalf of their client, which was that he was involved in Mr. bin Laden's legitimate activities but had nothing to do with terrorism.

They had sought unsuccessfully to have his trial separated from that of the bombers, and that issue will now be a basis of appeal, said one of the lawyers, Joshua L. Dratel.

Another, Sam A. Schmidt, said: "The jury was overwhelmed by the calamity of the event. They were overwhelmed by the carnage."

Mr. El-Hage's wife, April, who attended some of the proceedings in recent weeks, said by phone after learning of the verdict, "I don't believe my husband is guilty of what they accused him of."

She added: "It is completely against Islam, and he would never do something like this. It's against everything he believes in."

Prosecutors said the conspiracy grew out of a Muslim organization that had centers in Afghanistan and other places, including the Boerum Hill neighborhood of Brooklyn. Some of the members of that Brooklyn circle were arrested and convicted in the bombing of the World Trade Center in 1993 and in a plot to blow up other New York City landmarks.

The investigation of Mr. bin Laden evolved out of those earlier terrorism investigations by the United States attorney's office in Manhattan, which is why the trial of the embassy bombings, which occurred more than 7,000 miles away in Africa, ended up in New York, and why prosecutors are still seeking to bring Mr. bin Laden and 12 other fugitives in the case to New York to face charges.

Mr. bin Laden is the scion of a wealthy Saudi family who prosecutors say leads a group, Al Qaeda, that finances Islamic terrorism around the world. He is believed to be living in Afghanistan under the protection of the ruling Taliban.

As the day began yesterday, the jury, which had sent in frequent notes to Judge Sand over the course of its deliberations, signaled that a verdict might be near with another note asking for a particular exhibit pertaining to Count 302 — the final charge on the 107-page indictment.

Then, shortly after noon, the jury sent out another note. "Judge Sand," it said, "the jury has reached a verdict!"

Within minutes, the rows in the courtroom filled with visitors, including several dozen witnesses, victims and family members who had come to New York, some flown from Africa.

Several who had been injured walked in with canes, or were led by others because they were blind. There were no outbursts or sounds of emotion during the taking of the verdict, which included reading the names of the 224 victims, each representing individual murder counts, but some spectators clutched tissues or sat with their faces in their hands.

When the forewoman pronounced "guilty" for Counts 17 and 18 — the murders of Julian L. Bartley Jr., a college student working as an intern in the Nairobi embassy, and his father, Julian L. Bartley Sr., the consul general — his widow, Sue, and daughter, Edith, sat quietly, their eyes glistening, in one row.

When the forewoman pronounced "guilty" for Count 54 — the murder of Prabhi Gutpara Kavaler in the Nairobi attack — her husband, Howard, and their two young daughters cuddled in another row.

After the verdict, Sue Bartley said, "It was like a relief today to know that this part was over."

Her daughter, Edith, added, "While we are most pleased with the verdict, we know that the loss of life and grief that people will endure is not minimized by today's verdict."

Clara Aliganga, the mother of Jesse N. Aliganga, a 21-year-old Marine security guard who was killed in the Nairobi attack, said the verdict "doesn't erase the pain."

"I just hope it gets a message to the terrorists that we won't take this lightly," she said. "There will be justice."