Société Générale said on Thursday it had discovered €7bn ($10.26bn) of losses from a rogue trader in European stock futures and big US subprime mortgage writedowns, forcing the French bank into an emergency €5.5bn share issue.

Daniel Bouton, SocGen’s long-standing chief executive and chairman, offered to resign, but this was rejected by the board after reviewing the colossal losses – including €2.05bn of writedowns on exposure to US mortgages and bond insurers.