The three were accused of being part of a North American support cell that provided supplies, money and recruits to groups of Islamic extremists. The defense contended they were trying to help persecuted Muslims in war zones with relief and humanitarian aid.

The White House thanked the jury for a ''just'' verdict.

''We commend the jury for its work in this trial and thank it for upholding a core American principle of impartial justice for all,'' said Gordon Johndroe, a spokesman for the National Security Council at the White House. ''Jose Padilla received a fair trial and a just verdict.''

Estela Lebron, Padilla's mother, said she felt ''a little bit sad'' at the verdict but expected her son's lawyers would appeal.

''I don't know how they found Jose guilty. There was no evidence he was speaking in code,'' she said, referring to FBI wiretap intercepts in which Padilla was overheard talking to Hassoun.

Padilla was first detained in 2002 because of much more sensational accusations. The Bush administration portrayed Padilla, a U.S. citizen and Muslim convert, as a committed terrorist who was part of an al-Qaida plot to detonate a radioactive ''dirty bomb'' in the U.S. The administration called his detention an important victory in the war against terrorism, not long after the Sept. 11 attacks.

The charges brought in civilian court in Miami, however, were a pale shadow of those initial claims in part because Padilla was interrogated about the plot when he was held as an enemy combatant for 3 1/2 years in military custody with no lawyer present and was not read his Miranda rights.

Padilla's attorneys fought for years to get his case into federal court, and he was finally added to the Miami terrorism support indictment in late 2005 just as the U.S. Supreme Court was poised to consider President Bush's authority to continue detaining him. Padilla had lived in South Florida in the 1990s and was supposedly recruited by Hassoun at a mosque to become a mujahedeen fighter.

The key piece of physical evidence was a five-page form Padilla supposedly filled out in July 2000 to attend an al-Qaida training camp in Afghanistan, which would link the other two defendants as well to Osama bin Laden's terrorist organization.

The form, recovered by the CIA in 2001 in Afghanistan, contains seven of Padilla's fingerprints and several other personal identifiers, such as his birthdate and his ability to speak Spanish, English and Arabic.

''He provided himself to al-Qaida for training to learn to murder, kidnap and maim,'' said Assistant U.S. Attorney Brian Frazier in closing arguments.

Padilla's lawyers insisted the form was far from conclusive and denied that he was a ''star recruit,'' as prosecutors claimed, of the North American support cell intending to become a terrorist. Padilla's attorneys said he traveled to Egypt in September 1998 to learn Islam more deeply and become fluent in Arabic.

''His intent was to study, not to murder,'' said Padilla attorney Michael Caruso.

Central to the investigation were some 300,000 FBI wiretap intercepts collected from 1993 to 2001, mainly involving Padilla's co-defendants Hassoun and Jayyousi and others. Most of the conversations were in Arabic and purportedly used code such as ''tourism'' and ''football'' for violent jihad or ''zucchini'' and ''eggplant'' instead of military weapons or ammunition.

The bulk of these conversations and other evidence concerned efforts in the 1990s by Hassoun and Jayyousi, both 45, to assist Muslims in conflict zones such as Chechnya, Bosnia, Somalia, Afghanistan and Lebanon.

Hassoun is a computer programmer of Palestinian descent who was born in Lebanon. Jayyousi is a civil engineer and public schools administrator who is a naturalized U.S. citizen originally from Jordan. Jayyousi also ran an organization called American Worldwide Relief and published a newsletter called the Islam Report that provided details of battles and political issues in the Muslim world.

''It wasn't a terrorist operation. It was a relief operation,'' said Jayyousi attorney William Swor.