The UK's Financial Services Authority said today it had launched a review of the systems and controls at financial firms for dealing with market rumours despite its investigation into trading activity in UK bank HBOS during its rights issue failing to uncover evidence of deliberate market manipulation.

On the afternoon of March 19, the FSA launched an investigation into trading in HBOS after the bank's shares fell by 17% to 398p by 08.52am on that day as negative rumours swept the market.