In January Glencore revealed plans to place these open cut operations on care and maintenance which was estimated to eliminate 5 million tonnes per annum of production (half of Optimum’s 10Mtpa saleable output) and 1070 jobs at the time.

Months of subsequent consultations involving South Africa’s Commission for Conciliation, Mediation and Arbitration (CCMA), unions and government officials have not markedly changed the verdict.

“It was demonstrated during these sessions that these operations are financially not viable in the current market conditions and that there are no measures available to avoid the retrenchments,” Glencore said last week.

“Optimum will therefore be proceeding with the closure of some of the operations which will result in the retrenchment of between 600-700 employees. The affected operations will be placed on care and maintenance.”

Glencore has previously flagged that the Optimum’s underground mining operations were still economic.

“Optimum currently intends to retain sufficient mining operations and processing capacity to ensure the continued supply of coal to the Hendrina Power Station,” Glencore said.

“Glencore has agreed to provide funding to Optimum to enable Optimum to pay the full retrenchment costs as tabled at the CCMA and will offer assistance to affected employees through re-training programmes to enable them to plan for the future.

“This includes training in areas such as portable skills and financial management. The retrenchment packages offered are above the industry standard. Optimum will also consider redeploying some of the employees to other parts of the business should vacancies be available.”

The Optimum coal mining complex had an estimated workforce of 3700 employees in 2014.

Glencore has a separate target of cutting 15Mtpa of export coal capacity across its Australian mines in 2015 with jobs shed from the Ulan West, Mt Owen and Collinsville coal mines so far.