The list of “problem” banks grew by almost 50 per cent in the third quarter, the Federal Deposit Insurance Corporation reported on Tuesday, stoking fears that further bank failures could put the agency’s insurance fund under severe pressure.

Sheila Bair, FDIC chairman, suggested more failures were likely in spite of government support for the banking industry. While the US Treasury’s capital purchase programme would bolster bank capital levels and revive lending, she said the scheme was not intended to help banks that were not “viable”, such as those on the problem list.