Johannesburg - Aquarius Platinum, the world's fourth-biggest platinum miner, reported a lower half-year loss as a rise in output from its Kroondal mine in South Africa lessened the impact of a drop in prices of platinum group metals (PGMs).

Aquarius, which operates mainly in the strike-prone South African platinum belt, reported a headline loss of $22 million (R243 million) for the half year ended December 31, down from $56 million in the same period a year earlier.

Revenue slipped 2 percent to $113 million, while attributable production increased 7 percent to 168,014 PGM ounces.

PGM metals include palladium, iridium and other metals.

The average US dollar PGM basket price dropped 5 percent in the half-year from the same period a year earlier, Aquarius said, while the rand basket price rose 13 percent as the South African currency weakened.

The company said it was concerned that dollar-denominated metal prices fell despite a primary deficit in PGM metal markets during 2013, which is forecast to increase in 2014.

Aquarius said regulatory uncertainty in South Africa and Zimbabwe and the precarious state of South African industrial relations have also made longer-term planning difficult.

The world's top three platinum miners are trying to hammer out wage agreements with South Africa's largest labour body, the Association of Mineworkers and Construction Union, to end to a two-week strike that the country's Chamber of Mines says is costing the industry about $18 million a day in revenue.

Amcu members walked out at Anglo American Platinum, Impala Platinum and Lonmin on January 23.

Workers at Aquarius's main operations are not on strike. - Reuters