Enquiry demanded
Kerviel, who had been at the bank since 2000, allegedly used intricate methods to trade without the bank's authorisation on the world future markets.
The scale of the losses was eventually uncovered by back-office staff during a routine check. 
The French government has demanded a full accounting of the scandal over the fraud.
Societe Generale's losses dwarf those sustained by Barings, a British bank, in 1995.
Nick Leeson gambled away $1.5bn at Barings, causing it to collapse.