London's top flight index slid into the red as it succumbed to market jitters ahead of a meeting between oil suppliers over a potential production freeze.
The FTSE 100 Index slipped 21.4 points to 6343.8, as the falling oil price weighed on stocks amid concerns about the outcome of Sunday's meeting between Opec and non-Opec oil producers in Doha.
Brent crude was down one dollar and 13 cents to 42.71 US dollars a barrel, dragging oil giant BP down 2.6p to 355.9p, while miner Anglo American edged down 11.9p to 678.3p.
It comes as the market digested fresh data from China showing i ts economy grew at an annual rate of 6.7% in the first three months of the year, its slowest quarterly pace in seven years, but in line with market expectations.
Across Europe, Germany's Dax was down 0.4%, while the Cac 40 in France fell 0.3%.
The Dow Jones made marginal losses, as US banking giant Citigroup reported weak but better-than-expected results for the first quarter.
The pound was up 0.5% against the dollar at 1.42, while sterling also stepped up 0.2% against the euro at 1.25.
In stocks, housebuilders continued to dominate the FTSE 100 fallers board after analysts said on Thursday there were signs that Persimmon's sales were starting to slow.
Barratt Developments fell 12.5p to 509.5p, Taylor Wimpey was 4.3p lower at 172.7p, while Persimmon was down 30p to 1870p.
Falls also spread to the wider construction sector, with builders' merchants Travis Perkins down 86p to 1774, as official data showed construction in Britain fell for the second month in a row in February.
The Office for National Statistics (ONS) said output dropped 0.3% compared to the month before, due to falls in the amount of new work being carried out and repair and maintenance activity.
Elsewhere, retailer Mothercare showed signs of recovery after its shares slumped more than 20% on Thursday following tough trading in its international business.
The baby goods and maternity chain said sales fell in all four international regions in the 11 weeks to March 26. Sales were down by 9.7% with currency movements stripped out, or 10.8% lower in actual currencies.
However, in this session shares lifted more than 1%, or 2.5p, to 152p.
Supermarket giant Tesco edged up as it benefited from better-than-expected results from retailer Carrefour thanks to its performance in Brazil and southern Europe.
The French firm said revenues rose 3.1% on a like-for-like basis, excluding currency, calendar effects and fuel sales.
Shares in Tesco rose 1.9p to 179.6p.
SABMiller was the biggest riser on the FTSE 100 after an agreement was reached with the South African government to help secure regulatory approval for its takeover by AB InBev.
The £71 billion mega-merger would create the largest brewer in the world.
The biggest risers in the FTSE 100 Index were SABMiller up 67p to 4286p, Royal Bank of Scotland up 3.4p to 235p, Vodafone up 2.95p to 229.8p, Antofagasta up 6p to 471p.
The biggest fallers were Travis Perkins down 86p to 1774p, Ashtead Group down 34p to 814.5p, Berkeley Group down 114p to 2862p, Intu Properties down 10.9p to 296.5p.