The FTSE traded 56 points, or 1%, lower this morning at 5705.49 after a downbeat assessment of the US recovery from former Federal Reserve chairman Alan Greenspan.
The UK market's mood was dampened by comments yesterday from Greenspan that the US is "far from being out of the woods".
Jim Rogers, commodities fund manager and former colleague of hedge fund manager George Soros, added to the gloom by saying China and India could not carry a global economic recovery alone.
On the FTSE, Eurasian Natural Resources dropped 3.2% to £12.10p; Xstrata was down 3.1%, at £12.73; and Kazakhmys was also off 3.1%, at £15.54.
Investors had already taken profits yesterday on major metal and oil producers including BHP Billiton and Cairn Energy.
British Airways was the highest climber, up 0.5% to 238.7p, on news it had signed a definitive agreement for a $7.5bn merger with Spain's national carrier Iberia.
Poor news on US consumer credit from February and Greenspan's downbeat assessment of recovery led to the Dow Jones shedding seven points, or 0.8% of its value, to 10,897.52.
However, energy group EOG Resources gained 6.5% to $103.74 after predicting its output will rise in 2011.
In Asia, the Nikkei 225 fell 1.1%, or 124.63 points, to end trading at 11,168.2.
