JERUSALEM (Reuters) - An Israeli man was convicted on Tuesday of murdering a Palestinian teenager in Jerusalem, as a court rejected his insanity plea for a crime that helped trigger the 2014 Gaza war.

Prosecutors said Yosef Haim Ben-David organized the killing of 16-year-old Mohammed Abu Khudair. Two Jewish youths who helped him abduct the teen, who was bludgeoned, strangled and burned alive, were sentenced in February, one to life imprisonment and the other to a 21-year term.

All three defendants had confessed and said the July 2, 2014, murder was revenge for the killing days earlier of three Israeli youths by the Hamas Islamist group in the occupied West Bank.

Ben-David, 30, lodged an insanity plea that held up his formal conviction and sentencing. After receiving psychological assessments, the court ruled he "fully understood his actions" and found him guilty. He will be sentenced on May 3.

Abu Khudair's killing raised tensions, and a seven-week Israeli offensive against the Hamas-run Gaza Strip began on July 8, 2014, after cross-border Palestinian rocket attacks and an Israeli roundup of suspected militants in the West Bank.

(Reporting by Jeffrey Heller; Editing by Hugh Lawson)