A federal judge on Thursday increased the sentence of Lynne F. Stewart, a disbarred lawyer convicted of assisting terrorism, to 10 years  nearly five times as long as her original sentence.

An appeals court had ordered the judge, John G. Koeltl of Federal District Court in Manhattan, to resentence Ms. Stewart after it deemed his first sentence, of 28 months, too light.

Judge Koeltl, after speaking for about 45 minutes about the considerations he had made, the legal sentencing guidelines and the facts of the case, ordered Ms. Stewart to serve 120 months.

A collective gasp went up from Ms. Stewart’s supporters, who packed the broad, high-ceilinged courtroom. That was followed by a few shrieks and sobs; some held their hands over their mouths.