The former French investment banker’s trades cost his employer Société Générale €4.9 billion Kerviel has fought a 10-year legal battle against his former employer, alleging that his superiors were aware of his trading PARIS: Jerome Kerviel, the former French investment banker whose trades cost his employer Société Générale €4.9 billion, lost a legal bid Thursday to force a retrial following his 2010 conviction, a lawyer acting for the bank said. A French legal commission that deals with requests for retrials “has decided that there was nothing new, that Mr.Kerviel’s request was without basis,” a lawyer acting for Société Générale, Jean Veil, told reporters. Kerviel was sentenced to a five-year prison term in 2010, with two years suspended, for breach of trust, forgery and entering false data over his huge trading losses which he attempted to hide from the bank. The losses amount to $5.8 billion at current exchange rates. The former trader, now aged 41, has fought a 10-year legal battle against his former employer, alleging that his superiors were aware of his trading and then attempted to manipulate the judicial investigation afterwards. Kerviel, who was released from jail after four months behind bars, has lost two previous appeals against his convictions in 2012 and 2014.