FD is used by the bank on an ongoing basis, but it has seen its brief expanded to include crisis comms since the news of the huge trading loss broke on 24 January.
Société Générale confirmed it had been using FD, but the agency was unable to comment on the exact nature of its work.
The news comes as some City agency chiefs questioned the bank's stance on futures trader Jérôme Kerviel's alleged series of bogus transactions, which defrauded the bank.
Many praised the bank for its initial crisis comms work but said it could suffer in coming days:
‘My gut instinct is the first few hours were handled well as soberly as it could be,' said the City agency head, who did not want to be named. ‘It was kept secret until they wanted to tell the world.'
‘But,' he added, ‘to pin all the blame on Kerviel could mean the bank's problems have only just started. To be so unequivocal will have massive repercussions if it turns out this was not the work of just one man.'