It said South African regulatory approval had been obtained in support of the purchase.
The firm said the acquisition of its joint venture partner’s 50 per cent share in Hidden Valley and the surrounding tenement package in Papua New Guinea was in line with the company’s overall aspiration to increase its annual production profile to 1.5Moz within three years.
The firm said it plans to invest and develop stages five and six of the mine initially, mining approximately 1.4Moz ounces of gold and 27Moz of silver over a period of seven years.
The company believes that Hidden Valley has the potential to contribute approximately 180,000oz gold per annum to Harmony’s production profile, at an all-in sustaining cost of less than US$950/oz.
"Harmony has the skills and technology to successfully re-commission one of PNG’s most recent mine developments", chief executive officer Peter Steenkamp said.
It also announced that an update on the mine’s life plan will be included in Harmony’s production update, which will be released on November10, 2016.