HBOS is preparing to hand the Financial Services Authority its own detailed account of last week’s unusual trading patterns in the bank’s shares to aid the UK watchdog’s investigation into possible stock manipulation.

Shares in the UK bank plunged as much as 17 per cent last Wednesday when false rumours spread that it had sought emergency funding from the Bank of England. HBOS and the UK central bank categorically denied the rumours and the FSA launched an inquiry into potential market manipulation.