Al-Jaghbeer was first convicted in absentia in 2005, along with seven others, including Abu Musab al-Zarqawi, the slain leader of al-Qaeda in Iraq.
Two men convicted with him were executed in March 2006.
Al-Jaghbeer was re-tried after he was captured in Iraq and transfered to Jordan, but an appeals court overturned the second guilty verdict on procedural grounds and ordered a new trial.
In Monday's verdict, the court found that al-Jaghbeer facilitated contacts between al-Qaeda and an Amman cell that killed Foley.
Fathi Daradkeh, his lawyer, said he plans to appeal the verdict next week.
Al-Jaghbeer has also been tried separately for the deadly bombing of Jordan's embassy in Iraq in August 2003, in which 14 people were killed.