Societe Generale has today been ordered to pay €450,000 (£350,171) to former employee Jerome Kerviel on the grounds the ex-trader was unfairly dismissed, according to various reports.
Kerviel has previously been found guilty for breach of trust and fraud, with his unauthorised trades losing the bank €4.9bn in 2008 in an incident that is one of the largest of its kind.
The French court ruled that the bank fired the ex-trader without real cause.
However a Societe Generale spokesperson said: "This decision is incomprehensible and inconsistent with the decision of the Supreme Court [Cour de cassation], which has passed definitive sentence on Jerome Kerviel. It is counter to the facts that have been judged. We will appeal against this decision."
Décision incompréhensible et incohérente avec la Cour de cassation qui a définitivement condamné Jérôme #Kerviel. Nous annonçons faire appel— Société Générale (@SocieteGenerale) June 7, 2016
Meanwhile, Kerviel's lawyer David Koubbi told Reuters this most recent court decision "tore apart the story which Societe Generale has presented from the beginning".
Kerviel was convicted for his actions in 2010, and sentenced to five years in prison, two of which to be served as a suspended sentence.
However, Kerviel did not actually go to prison until 2014, and not until after he had embarked on a trek between Rome and France to meet Pope Francis, on what the ex-banker dubbed a crusade against the "tyranny" of financial markets.
Kerviel then spent a weekend lingering around the French-Italian border, refusing to cross into France unless he heard personally from President Francois Hollande, before finally turning himself over to the French authorities.
In September 2014, he was released from prison after just five months.
In the past, Kerviel has maintained that he did carry out the unauthorised trades, but argued that his former employer knew all about them, choosing to turn a blind eye when they were going well but to treat him as a scapegoat when things went wrong.