ALD Automotive's owner, the French bank Societe Generale, says a futures trader has defrauded it of more than $7 billion in one of the biggest financial frauds in history.

The bank says the trader has confessed to the fraud and is being dismissed.

The bank is also firing top executives responsible for supervising the so far unnamed trader.

The bank also revealed it will report a near $3 billion loss stemming from bad investments in the US sub-prime mortgage market.