World markets were under pressure today as uncertainty about Chinese economic prospects led investors to take profits following a recent rally.
There were also fresh fears about the health of the financial sector after a leading Wall Street analyst downgraded major US bank Wells Fargo in the wake of third quarter figures.
The FTSE 100 Index fell 74.9 points to 5182.9 as London and a number of other exchanges posted losses of more than 1%.
While output figures in China were seen as mostly encouraging, analysts said Chinese exports and private investment continued to falter as the economy continued to rely on huge government stimulus spending.
Miners fell heavily by mid-morning, with Lonmin among those on the way down - off 39p at 1652p after news of a 20% decline in fourth-quarter production. Kazakhmys dropped 35p to 1248p and Fresnillo fell 26.5p to 791.5p.
Meanwhile, pub groups Punch Taverns, Enterprise Inns, Marston's and Greene King rose sharply in the FTSE 250 Index after the OFT ruled in the industry's favour following a CAMRA super complaint about beer ties.
The watchdog said it found no evidence that "tied" prices - where pub companies compel tenants to buy drinks from them - were harming competition for consumers.
Enterprise shares jumped 17% or 20.1p to 139.2p, while Punch rose 10.6p to 95.4p and Marston's added 2.25p to 93.25p.
National Express shares were back under pressure after the company said full-year results were likely to be weaker than it previously expected. Shares in the takeover target fell by 14.5p to 401p.
There was also a drop of 4% for nightclubs operator Luminar after pre-tax profits in the six months to August 27 plunged to £4.9m (€5.41m) from £8.4m (€9.27m) a year earlier as rising unemployment caused like-for-like sales to dive 4.5%.
Shares were 3.75p lower at 80.25p.