Mining stocks led the FTSE 100 Index into the red today amid mounting expectations that America will launch much-feared plans to scale back its economy-boosting drive next week.
Falling metal prices hit the heavily-weighted commodity sector and investors chose to stay on the sidelines ahead of Wednesday's US Federal Reserve decision on the future of stimulus measures.
Continuing uncertainty over US involvement in the Syria crisis added to investor nerves, with the FTSE 100 Index closing 5.2 points lower at 6583.8
Traders were also digesting rumours that hawkish Larry Summers is in line to take over from Ben Bernanke as chairman of the central bank in January.
In currency news, robust construction figures pushed the pound to its highest level against the euro for eight months, at just over 1.19.
The economic optimism also saw sterling reach 1.59 US dollars - its strongest since early February.
Miners dominated the FTSE 100 fallers board due to concerns that US tapering will deal a blow to global economic prospects and therefore demand for commodities.
Anglo American led the declines, off 52p to 1568.5p, while BHP Billiton dropped 38p to 1885p.
Nurofen and Strepsils owner Reckitt Benckiser posted the biggest gain in the top flight, up 102p to 4554p, a rise of more than 2%.
Other risers included ITV as the broadcaster continues to test record highs on the back of improved advertising conditions and production successes. Shares were 2% higher, up 3.8p at 183.4p.
Housebuilders also continued to surge as investors brushed off calls for a 5% cap to be placed on annual house price growth amid fears that the country is heading for a "bubble".
FTSE 100 -listed Charles Church owner Persimmon added 12p to 1162p, while in the second tier, Barratt Developments was 15.9p stronger at 330.9p and Crest Nicholson lifted 12.2p to 337.2p ahead of results next week.
In a quiet session for corporate news, pubs chain JD Wetherspoon was 17p higher at 752p as it announced record underlying profits and sales for the last financial year.
But it said growth was likely to be subdued for the year ahead, after a recent slowdown in like-for-like sales growth to 2.5% in the two weeks to September 8, as it comes up against strong numbers from a year earlier.
Meanwhile, oil and gas engineering firm Kentz Corporation dropped 7p to 492p in the FTSE 250 Index after Stuttgart-based M+W followed Amec in walking away from a potential takeover offer worth up to a £690 million.
The biggest FTSE 100 risers were Reckitt Benckiser up 102p to 4554p, ITV ahead 3.8p at 183.4p, Land Securities 13.5p higher at 922p and British Land 8.5p up at 582.5p.
The biggest FTSE 100 fallers were Anglo American down 52p to 1568.5p, Morrisons off 7.2p to 295.3p, BHP Billiton 38p lower at 1885p and John Wood Group down 16p at 807p.