The FSA's chairman Lord Adair Turner warned Barclays earlier this year its reputation in the wider market was being damaged by its own submissions to banking bodies and its handling of trading books.
Barclays former chief executive Bob Diamond has opted to give up a deferred bonus owed to him from his former bank, worth up to £20m.
The Royal Bank of Scotland (RBS) is fighting against a court order which requires it to co-operate with an international criminal investigation into rate-fixing.
The FTSE 100 has risen in early trading, building on recent gains, but Barclays' share price remains volatile as investors react to CEO Bob Diamond's resignation.
Global markets bounced back sharply last month, with some of the most heavily sold off equities in Europe up by huge margins.
Investors piled into risk assets today as the results of last night's summit talks in Europe gave investors hope that an end to the crisis is in sight.
European equities lost ground in afternoon trading ahead of a crucial EU summit, as Spain officially asked its eurozone neighbours for a bailout.
World markets including the FTSE fell in early trading as weak economic data and Moody's downgrade of 15 banks unnerved investors.
The FTSE 100 fell alongside other major markets across Europe today, after the Federal Reserve cut its growth forecast for the US economy.