A trader accused of causing huge losses at French bank Societe Generale is under police protection, the country’s finance minister said today, while the bank’s legal troubles have expanded to the United States.

Accused French rogue trader Jerome Kerviel told police his Societe Generale bosses must have been aware of his massive risk-taking on markets but turned a blind eye as long as he earned money, a judicial official said tonight.

Investigating judges filed preliminary charges against a trader accused of causing billions of euros in losses at France's second-largest bank.