PARIS, Oct 30 (Reuters) - Trader Boris Picano-Nacci was heard by a magistrate on Thursday in conjunction with a probe into a 750 million euro ($979 million) loss at Groupe Caisse d'Epargne, said a legal source briefed on the matter.
Picano-Nacci, a 33-year old who worked on the trading desk of the bank, was held for questioning over the incident. He could not be reached for comment.
The Paris prosecutor's office said earlier this week that it had opened an investigation after Caisse d'Epargne filed a lawsuit against persons unknown for breach of trust at the bank.
The Caisse d'Epargne trading loss recalled an earlier scandal this year when rival Societe Generale (SOGN.PA) revealed 4.9 billion euros of losses, which it said were caused by unauthorized trades by Jerome Kerviel, a junior trader at SocGen.
French President Nicolas Sarkozy and Economy Minister Christine Lagarde expressed their anger at the Caisse d'Epargne loss and the bank's chairman, chief executive and finance head all resigned on Oct. 19 following the political criticism.
Caisse d'Epargne said the loss had been caused by a small team of traders. The traders made a wrong bet on the direction of the stock market and had exceeded their trading risk limit.
Caisse d'Epargne is planning to merge with rival French mutual lender Banque Populaire.
Caisse d'Epargne and Banque Populaire both have stakes of 35 percent in Natixis (CNAT.PA), the French investment bank that has been hit hard by the credit crisis. (Reporting by Thierry Leveque)