South Africa's Harmony Gold said on Thursday it swung into quarterly profit as production inched up and a weaker rand currency offset declines in the dollar price of bullion.

Headline earnings per share - which strips off certain one-off items - reached 17 cents in the three months to December from a loss of 1.20 rand in the previous quarter.

South African mining companies benefit from mostly cheaper costs because they are paid in the rand and earn higher income from sales of their commodities in dollars.