Harald Espenhahn, who was chief executive of the company's Italian arm, received the highest sentence of 9 years and 8 months in prison. Five others were given sentences of between 6 and 7 years. The ruling is final and cannot be appealed.

In previous rulings, the court justified the convictions by saying that the workplace was unsafe and that emergency services at the plant had been reduced.

Relatives of the victims burst into tears when the court ruling was read out.

The trial process for the 2007 fire has been widely followed in Italy in part because of the outrage expressed by relatives of the victims, who have said they hope the case will set a tough legal precedent for industrial accidents.

(Reporting by Steve Scherer, editing by David Evans)