FRANKFURT, Germany - A Moroccan man convicted of helping the Sept. 11 suicide pilots will appeal his latest conviction to Germany's highest court, his lawyer said Sunday.

Mounir el Motassadeq already was sentenced to seven years in prison on a conviction for membership in a terrorist organization. He was found guilty by an appeals court Thursday of an additional 246 counts of accessory to murder.

The Federal Court of Justice ruled Motassadeq was aware that pilots Mohamed Atta, Marwan al-Shehhi and Ziad Jarrah planned to hijack and crash planes. El Motassadeq was a close friend of the three hijackers when they lived and studied in Hamburg, Germany. He has acknowledged training at an al-Qaida camp in Afghanistan but insists he knew nothing of their plans.

Judge Klaus Tolksdorf ruled that el Motassadeq had helped "watch the attackers' backs and conceal them" by doing things such as helping them keep up the appearance of being regular university students - paying tuition and rent fees, and transferring money. Tolksdorf said it was irrelevant to el Motassadeq's guilt whether he knew of the planned timing, dimension or targets of the attacks.

The appeals court sent the case back to the original trial court in Hamburg for revised sentencing. Motassadeq could see his prison term extended to 15 years.

Attorney Ladislav Anisic said Sunday the 32-year-old will take his case to the Federal Constitutional Court.

"So long as he is alive, our client wants to fight for people to believe him," Anisic said in a telephone interview.

El Motassadeq has spent a total of about three years in prison.