Dec. 5 (Bloomberg) -- Jerome Kerviel, blamed by Societe Generale SA for its record trading loss, was denied permission by investigators to question the bank’s Chairman Daniel Bouton, a lawyer for the former trader said today.

Caroline Wassermann said in a telephone interview that Kerviel’s legal team is deciding whether to appeal the decision.

Kerviel is under investigation by judges Renaud Van Ruymbeke and Francoise Desset for his role in the bank’s 4.9 billion-euro ($6.3 billion) loss. While he has admitted to taking positions that exceeded his trading limits, faking documents and evading internal controls, the 31-year-old says the bank was aware of what he was doing and that most of the loss was due to the decision to sell his stakes over three days of falling markets.

The defense team exercised its right under French rules to ask the investigating judges to pursue specific lines of inquiry in an effort to prove that allegation. In addition to Bouton, his lawyers have called on the bank’s auditors and the trader who liquidated Kerviel’s positions. The defenders have also sought to leverage a private report by France’s Banking Commission, which fined the bank 4 million euros in July for failing to comply with rules on internal controls.

Bouton, 58, stepped down as chief executive officer in May, while retaining his position as chairman. He’d held both roles since 1997 and his offer to resign after the bank revealed the trading loss was turned down twice by the board. An internal investigation commissioned by the bank showed the bank had failed to follow up on at least 75 warnings on Kerviel’s positions.

Jean Veil, a lawyer for Societe Generale didn’t immediately return a call for comment.

Kerviel is scheduled to be questioned by Societe Generale General Counsel Gerard Gardella Dec. 8 at a closed door meeting with the investigating judges.

Kerviel faces charges including breach of trust, falsifying documents and hacking the bank’s computers to input faked information. He spent five weeks in preliminary detention at Paris’s Sante prison, during which he was fired. He is now working at a computer services company owned by a specialist who had advised his defense.

To contact the reporter on this story: Heather Smith in Paris at hsmith26@bloomberg.net

Last Updated: December 5, 2008 07:07 EST