A Frenchman convicted in one of history's largest trading fraud cases has emerged from a prison south of Paris on conditional release before being equipped with an electronic bracelet to monitor his movements.

Jerome Kerviel left France's Fleury-Merogis prison, where he was held apart from other inmates, and said Monday he was "super happy" about the release. He will have freedom of movement on weekends and during the day on weekdays.

Kerviel cost Societe Generale 4.9 billion euros ($7 billion at the time) in losses in 2008, just as the global financial crisis was growing. He claims the bank had quietly welcomed his unauthorized trades when they made money, but turned against him when they turned sour.

Kerviel said he would "fight" to try to prove wrongdoing by the bank.