Surprising UK growth figures sent the pound soaring today, but the news failed to offset falls on the FTSE 100 Index.
The 0.8% rise in third quarter gross domestic product (GDP), based on provisional estimates by the Office for National Statistics, was double the 0.4% expected.
While the pound received an immediate boost, the Footsie retreated into the red - down 44.7 points to 5707.3 - after a decline in US house prices and disappointing earnings from banking giant UBS.
Wall Street's Dow Jones Industrial Average was also under pressure after a home-price index revealed a 0.1% drop in houses prices in August.
Sentiment was further hit after UBS posted an overall profit in the third quarter of 1.66bn Swiss francs (€1.2bn1), but its investment bank, which employs 6,300 at its London headquarters, suffered a loss of £265m (€302.9m).
Sterling jumped more than 1% against other major currencies following the better-than-expected UK growth figures and after ratings agency Standard & Poor's revised its outlook on the UK from negative to stable.
The pound reached US$1.59 and €1.14, with today's GDP data indicating the Bank of England will hold off from taking further emergency action to prop up the economic recovery.
The banking sector saw falls in the wake of the UBS update, with Barclays down 4p to 277.4p, Royal Bank of Scotland off 0.6p to 44.8p and HSBC off 8.4p to 660p.
The biggest fall in London, however, was recorded by Cairn Energy after an update on its Greenland exploration activities disappointed investors.
Shares dropped 7% - off 29.5p to 382.5p - after two wells were abandoned and another did not reach its target depth before the end of the Arctic drilling season, although it stressed operations may resume next year.
Other top flight fallers included Arm Holdings, despite better than expected third quarter profit and sales figures as it benefits from demand for its microchips in mobile phones and other gadgets.
Shares were 23p lower at 366.2p as analysts said the current share price reflected much of the upside in the stock.
Insurance firms were also under pressure after a downbeat review of the sector by brokers from Bank of America, prompting Legal & General to fall 1.3p to 101.5p and Prudential to drop 10.5p to 621.5p.
Outside the top flight, shares in transport group Go-Ahead were 7% higher after it reported "robust" current trading and said it had identified the successor to chief executive Keith Ludeman, who is due to retire in July. Shares rose 85p to 1358p.
Brit Insurance lifted 24p to 1045p after directors recommended that shareholders accept a private equity offer worth up to £888m (€1.015bn).
The biggest Footsie risers were Carnival up 114p to 2768p, Pearson ahead 18.5p to 966p, Vodafone up 1.5p to 167.4p and Kazakhmys ahead 11p to 1391p.
The biggest Footsie fallers were Cairn Energy down 29.5p to 382.5p, Arm Holdings off 23p to 366.2p, BHP Billiton down 56p to 2196.5p and Cobham off 6.1p at 239.4p.