Alan Greenspan, chairman of the US Federal Reserve and viewed as one of the main architects of the bull market in global stock markets over the past decade, almost became the villain of the piece yesterday.

Mr Greenspan's army of admirers, which includes most of the legion of stock market traders in London, were looking slightly sheepish yesterday after his comments on US monetary policy to the US House Banking Committee, triggered another sell-off in the bond market and drove global markets lower.

In his biannual Humphrey-Hawkins testimony to Congress, Mr Greenspan said he remained worried that inflation could re-emerge if US unemployment continued to fall and warned that the Fed would act quickly in such an event.

As the Greenspan news reached London the main indices fell afresh and posted further losses across the board. The benchmark index, the FTSE 100, posted a fifth decline and dropped back below the 6,300 mark.