The German Court of Appeals in Hamburg is expected Monday to pronounce the sentence of Mounir al-Motassadek, who is convicted of participating in the 9/11 attacks in the US.
The German court opened last week sentencing hearings for Motassadek after his conviction as an accessory to murder in the attacks.
The Morrocan could get up to 15 years in prison. In 2006 Motassadek was found guilty of abetting the murder of 246 people on the four planes that crashed on 11 September 2001.
Motassadek was originally jailed for 15 years in 2003, convicted of helping the 11 September plotters, who were based in Hamburg, with logistical support and other aid.
But that verdict was overturned by Germany's Supreme Court in 2004 and a retrial ordered.