French bank Societe Generale has been ordered to pay about 450,000 euros ($510,000) to former trader Jerome Kerviel for unfair dismissal, after he was accused of unauthorized trades that caused the bank billions in losses.

Supporters of Kerviel hailed the decision Tuesday by a labor arbitration council, while Societe Generale called it "incomprehensible" and vowed to appeal.

It's part of a web of ongoing legal cases involving Kerviel since his trades in 2007 and 2008 spiraled into massive losses. The bank insists it wasn't aware of his actions, but Kerviel argues that his superiors knew what was going on. He has become an icon for critics of the banking world.

Kerviel sued for wrongful dismissal, and the court said he was fired "without real and serious cause."