* Copper up 2 percent year-on-year
* Kumba Iron Ore output down 19 percent due to Sishen strike
* No update provided on Minas Rio
LONDON, Jan 25 (Reuters) - Copper and coal provided relative bright spots for Anglo American on Friday, as the mining group reported quarterly production badly dented by the strikes that battered South Africa's mining industry last year.
Copper - where it continued to suffer the impact of troubles at its Chilean Collahuasi mine - posted a better than expected rise to 172,900 tonnes, up 2 percent year-on-year, while coal production climbed across the board, broadly in line with forecasts.
There was, as expected, worse news for Anglo's South African units, which have been badly hit by labour unrest there and will be a top priority for incoming chief executive Mark Cutifani.
Iron ore, which was the largest contributor to Anglo's profit in 2011, saw production tumble 19 percent, with the group's South African Kumba Iron Ore unit producing a total of 9 million tonnes of the steelmaking ingredient. Strikes at Kumba's key Sishen mine cost it 5 million tonnes.
In platinum, Anglo is battling labour troubles but also margins squeezed by costs and low prices. The keenly watched unit saw production fall 29 percent. Two months of labour unrest last year cost it 272,590 ounces of platinum production.
Anglo has unveiled plans to tackle losses at its platinum arm, slashing jobs and mothballing mines. It is currently in consultation with governments and unions.
Friday's numbers illustrate the size of the challenge ahead for new arrival Cutifani, who will be tasked with radically improving the company's lagging share performance, after outgoing boss Cynthia Carroll left under pressure from shareholders over poor returns.
One key item on his list will be flagship iron ore project Minas Rio in Brazil, but the company did not provide updated details on development costs, expected to exceed $8 billion, or timing. The project - a bruising top-of-the-market deal that contributed to Carroll's fall from grace - has been hit by delays and cost overruns and its value is expected to be written down before Anglo's 2012 results are released in February.
Another top item on Cutifani's to-do list will be improving operational performance in copper, a key contributor to Anglo's bottom line that has suffered from declining grades and the underperformance of Collahuasi, the mine it controls with Xstrata.
Collahuasi was hit by work stoppages, heavy rains and fatal accidents last year, prompting Anglo, Xstrata and Japanese partner Mitsui to step in. Production there down 36 percent year-on-year but up 17 percent on the third quarter.
Diamond production rose by 24 percent, as the group resumed operations at its Jwaneng mine, while nickel fell by a quarter after losing its Loma de Niquel concessions in Venezuela.