London's FTSE 100 Index dropped into the red following heavy falls on Wall Street, as third quarter figures from US giants disappointed investors.

Lacklustre earnings reports from McDonald's and General Electric sent the Dow Jones Industrial Average 1% lower, with traders still reeling after Google shocked the market with a 20% earnings fall in results that were released earlier than planned due to a glitch.

The Footsie broke its four-day winning streak to close 20.9 points lower at 5896.2 as it was also weighed down by bank stocks amid fears over soaring bills for mis-selling of payment protection insurance (PPI). There was little cheer for stocks from news that UK government finances improved last month, with borrowing down to £12.8 billion in September, as experts said Chancellor George Osborne was still likely to miss his annual target.

The pound gained strength from the better-than-expected borrowing data, lifting to €1.23, although it eased to $1.60.

In London, Barclays was nearly 3% or 6.9p lower at 233.9p after Thursday's news of another £700 million to cover the cost of rising PPI claims. Lloyds and Royal Bank of Scotland also saw share falls due to concerns they may have to set aside further provisions,

Lloyds fell 1.4p to 40.5p as analysts at Investec Securities warned the part-nationalised player could face another £2.3bn in PPI claims.

Fellow taxpayer-backed bank RBS fell 6p to 281p.

Temporary power supplier Aggreko was the biggest faller on the Footsie, down 7% or 165p to 2137p after it warned over profits. The group reported underlying sales growth of 13%, but said increasing bad debts and a currency hit would impact on full year profits by 2.5%.Renewed global demand fears and falling copper prices hit miners hard, with Evraz down 10.6p to 248.3p and Eurasian Natural Resources 10.9p lower at 348.9p.

Outside the top flight, William Hill jumped 4% after a good performance from football results The UK's largest bookmaker reported a 26% rise in operating profits in the quarter to September 25. Shares were up 14.1p at 357.5p.

Fellow second-tier stock Redrow fell 4% or 6.1p to 156.4p following news after market close last night that boss Steve Morgan's plans to buy back the housebuilder had fallen through and takeover talks were over.

The biggest Footsie risers were Johnson Matthey, up 42p to 2329p, and Hammerson ahead 7.3p to 483.4p.