The FTSE was 0.9% or 50.47 points lower in early trading at 5383.26 amid fears Europe's austerity measures will slow the global recovery.
Miners led the FTSE's decline with Xstrata off 3.4% at £10.59, Antofagasta 2.3% lower at 935p while Kazakhmys dropped 2.9% to £12.90.
Among others to lose ground, Lloyds Banking Group shed 2.6% to sit at 58.9p.
Risers this morning among the UK blue chips included Wolseley, up 7.3% at £17.26, after it announced trading profit for the year to 31 July 2010 would beat analysts' forecasts of £374m.
Compass Group also edged higher by 0.1% to 559.5p on news UBS had raised its recommendation for the world's biggest catering firm to 'buy', from 'neutral'.
Vodafone was up marginally, by 0.1% to 138.1p, on news a senior manager at its Indian subsidiary may sell his stake in the branch.
In the US overnight, banks weakened amid concerns over the SEC's widening investigations, currently centred on eight major banks, over the marketing and packaging of mortgage-related instruments.
JP Morgan declined 2.1% to $40.81, while Goldman Sachs was down 1.7% at $144.65.
Cisco Systems reported better than expected earnings, but its shares still fell 4.7% to $25.53 on disappointing sales forecasts.
In Asia, the Nikkei 225 was 1.5% lower at 10,462.51 points as Sony missed forecasts on profits, while concerns persisted over Europe.
Sony fell 6.8%, its sharpest fall in a year, as Barclays Capital, Goldman Sachs and Nomura all cut price targets.
Mazda Motor, which derives about one fifth of its sales from Europe, sank 1.9%.
