The US Federal Reserve cut a key interest rate by a half-percentage point.
The decision on Wednesday takes the overnight bank lending rate to 1% - the lowest since June 2004.
The Fed has cut benchmark overnight rates from 5.25% in nine steps over the past 13 months to counter a financial crisis that started with the collapse of the US mortgage market and spread around the world.
The Fed hopes the cut will help get credit flowing and "should help over time to improve credit conditions and promote a return to moderate economic growth".
But the BBC reports the bank is running out of interest rates that it can use as a tool for stimulus in future.
