New figures on industrial production have raised more concerns about the US economy.
The Federal Reserve said US industrial production tumbled by a bigger than expected 1.1% in August due to a big drop in car production and a slide in output from utilities due to mild temperatures.
Separate data published by the New York Federal Reserve showed that manufacturing in New York state unexpectedly contracted in September.
The drop in August was the biggest decline in US industrial production - which includes factories, mines and utilities - since September 2005. Analysts were expecting a 0.3% slide. Manufacturing output fell 1%, also the largest decrease in three years, as car production plummeted by 11.9%.
