The FTSE 100 Index fell for the fifth session in row, closing down another 11.6 points to 6498.3, with little cheer offered from George Osborne's autumn statement.
Figures showing the US economy grew faster than initially estimated in the third quarter fuelled worries that the Federal Reserve will taper its quantitative easing drive, with tomorrow's key jobs data also set to beat expectations.
The FTSE 100 has fallen nearly 5% since its recent peak in October as world markets have been hit by the US taper concerns.
Attention was focused on Mr Osborne's Autumn Statement, in which he revealed that the fiscal watchdog believes the UK will grow by 1.4% this year, compared with the Budget forecast of 0.6% in March.
Next year's GDP figure will be 2.4%, up from the previous 1.8% estimate, triggering an upgrade to borrowing forecasts.
The Office for Budget Responsibility predicted the UK budget deficit would be wound down to produce a surplus in 2018/19 for the first time in 18 years.
Whilst the Chancellor was on his feet in the House of Commons, the Bank of England announced that it had kept interest rates at 0.5% and left its quantitative easing programme at £375 billion.
The pound was left lower against most major currencies after the rate decision, edging lower to 1.63 US dollars and 1.19 euros.
Housebuilders were among those to benefit in the wake of the Chancellor's speech after he announced new loans worth £1 billion to unblock housing developments including in Manchester and Leeds.
Barratt Developments was 4.9p higher at 324.7p and Taylor Wimpey added 2.4p to 106p.
In the FTSE 100 Index, supermarkets remained under pressure, with Tesco down another 6.9p to 333.2p.
Morrisons was lower at 257.8p and Sainsbury's fell 3.1p to 389.9p.
Elsewhere, Next declined 75p to 5470p and Marks & Spencer slipped 1p to 474.3p.
Low-cost airline easyJet's load factor was down slightly at 89%, but its shares rose by 2p to 1409p,
Luxury handbags maker Mulberry fell 6p to 1019p after it posted a 28% fall in half-year profits to £7.2 million.
It blamed the cost of overseas expansion for the decline, but said it was encouraged by sales trends in its retail stores.
The biggest FTSE 100 risers were Shire up 53p at 2707p, Meggitt ahead 9.2p at 489.5p, Experian 20p stronger at 1097p and TUI Travel 6.3p higher at 374.6p.
The biggest FTSE 100 fallers were Petrofac down 44p to 1152p, Tesco off 6.9p to 333.2p, William Hill 7p weaker at 379.8p and Babcock International 20p lower at 1268p.