* Increases volumes in five of seven key commodities
* Impact of S.African stoppages to be seen in Q4
* Strikes to hit production, drive up costs
LONDON, Oct 25 (Reuters) - Miner Anglo American reported increased volumes in five of its seven key commodities while bracing for the full impact of South African strikes on platinum and iron ore output.
Anglo's labour woes - compounded by nagging concerns over its Minas Rio iron ore project in Brazil and operational trouble in Chile - have revived long-standing concerns among some investors over the group's exposure to South Africa.
Its management is already under fire over the group's underperforming share price.
Labour troubles across the South African mining sector spread to Anglo American Platinum, the world's top producer of the precious metal, last month, just before the end of the current reporting period.
Weeks later, they hit Anglo's Kumba Iron Ore unit, which alone accounted for almost half the group's operating profit in the first half.
Kumba's Sishen mine has since begun to ramp up operations, but Amplats workers have not yet returned to Amplats' Rustenburg, Union and Amandelbult mining operations.
Anglo said iron ore production for the three months to the end of September rose 14 percent to 12.5 million tonnes. The illegal strike at its Sishen began only at the start of October.
Over the month so far, though, the key South African miner has lost 2.2 million tonnes of finished product.
Platinum production, meanwhile, was flat, again in line with forecasts, at 649,000 ounces, though Anglo cut its production target for the year, trimmed planned spending and warned unit costs increased by 8 percent in he third quarter.
The strike caused the loss of 42,000 ounces of equivalent refined platinum in the third quarter, and an additional 96,300 ounces from disruption so far this month.
Copper, however, was a brighter spot for Anglo, despite ongoing operational trouble at Chile's Collahuasi, where it has now intervened with partner Xstrata to resolve operational, management and safety concerns.
The miner produced 157,300 tonnes of copper, up 12 percent and broadly in line with analysts' expectations, helped by the ramp-up of Los Bronces and despite a 40 percent drop in its share of production Collahuasi.
On the coal side, export metallurgical coal production increased by 12 percent to 4.5 million tonnes, and export thermal coal production from South Africa rose 10 percent to 4.6 million tonnes.
Diamond production, as expected, dropped by almost a third on last year to 6.4 million carats, largely due to poor market conditions as a lack of credit holds back buyers of rough diamonds and the polished market softens.
Anglo shares were up 1 percent after the results, which analysts were broadly in line with expectations, changing hands at 1,896 pence at 0705 GMT, against a flat FTSE 100 and a 0.6 percent rise in the broader mining sector.