Lonmin has lost around 5% after the platinum miner issued an unexpected update and cut its production guidance for the year.
It has suffered problems at its Karee operations after what it calls illegal industrial action, and had hoped to make up any production lost in March and April in the second half of 2011. Now it says it has completed an assessment of the impact on production and believes there will be a full year shortfall of 30,000 ounces of platinum due to this "one-off event." It hopes to get back to normal levels of production by August.
But this means it now expects a lower level of full year sales of around 720,000 ounces, and says it will exceed the expected 8% increase in unit costs.
The shares are currently down 74p at £14.70.
With miners already weaker after lower than expected Chinese copper imports, the market was already under pressure.
Apart from the Lonmin impact, investors are now having to fall a sell-off on Wall Street. The US market is now down around 140 points and the Dow Jones Industrial Average has fallen below the 12,000 level for the first time since March on global growth worries.
The FTSE 100 is down 75.14 points at 5781.20 as it heads towards the final half hour or so of trading.
