The day after getting the case, a federal jury in Manhattan on Wednesday convicted accused al-Qaida propagandist Suleiman abu Ghaith of conspiring to kill Americans by making jihadist videotapes in the aftermath of Sept. 11.

The government said abu Ghaith was the most senior al-Qaida official to go on trial in a civilian court since Sept. 11.

Abu Ghaith, 48, a charismatic Kuwaiti cleric who married Osama bin Laden's daughter, was best known for a Sept. 12 video he made in front of a cave with bin Laden and two other al-Qaida leaders, warning Americans that "a great Army is gathering against you."

He testified at his trial last week, contending that on Sept. 12 and in subsequent 2001 video and audio recordings he was merely articulating Muslim principles of self-defense and explaining the attacks. He said he never joined al-Qaida or knew of plots in advance.

Prosecutors did not accuse abu Ghaith of playing any part in Sept. 11, but said he used his fiery oratory to try to recruit fighters for al-Qaida. Although there was no evidence of it, they also said he knew about a plot to explode shoe-bombs on planes when threatening a "storm of airplanes" would continue in late 2001.

In addition to conspiracy to kill Americans, abu Ghaith was also convicted of conspiring to provide material support and of actually providing material support to al-Qaida.

He faces a possible life sentence in prison.