Armed Sunni Palestinian group is thought to have links to al-Qaeda.
The court had convicted al-Jaghbeer in absentia and sentenced him to death, but Jordanian law allowed him to be retried in 2005 after he was caught and extradited to Jordan.
At the retrial, al-Jaghbeer, 36, denied the charges of plotting terrorist actions that led to Foley’s killing.
His lawyer, Fathi al-Daradkeh, said the sentence was meant to “please the Americans, especially that it came a day after Annapolis“, referring to the US-sponsored Middle East summit which re-launched Palestinian-Israeli peace negotiations.
In a separate trial earlier this month, Palestinian-born al-Jaghbeer was sentenced to death for the Jordanian Embassy bombing in Baghdad in 2003 that killed 19 people.
Al-Jaghbeer is thought to be a part of a cell linked to Abu Musab al-Zarqawi, the Jordanian-born al-Qaeda chief in Iraq who was killed in a US air attack outside Baghdad in 2006.