A federal appeals court on Monday set aside two of three convictions against a former personal assistant to Osama bin Laden.

The U.S. Court of Appeals for the District of Columbia Circuit issued the ruling in the case of Ali Hamza al-Bahlul, who produced propaganda videos for al-Qaida and assisted with preparations for the Sept. 11, 2001, terrorist strikes.

A military commission had convicted him of conspiracy to commit war crimes, providing material support for terrorism and soliciting others to commit war crimes. He has been sentenced to life imprisonment.

The appeals court rejected al-Bahlul's challenge to his conspiracy conviction but overturned his material support and solicitation convictions.

The court, in an opinion by Judge Karen LeCraft Henderson, said the government had offered little backup for the notion that a military commission could try defendants on the charges for which the convictions were overturned — material support for terrorism and solicitation to commit war crimes.

On the conspiracy conviction, the appeals court said Congress has positively identified conspiracy as a war crime.