Two strikes began on March 5 at the company’s Matla and Arnot mines in Mpumalanga. Workers are striking because they did not receive performance bonuses, but Exxaro said the employees were aware of their performance levels and targets and did not receive the bonus because targets were not met.

Just three days later, employees at Exxaro’s Grootegluk mine in Limpopo began a walk-off. Exxaro said the strike involved “a range of grievances.”

Production also stopped at the Leeuwpan mine from March 9 and Inyada from March 11.

Exxaro said in a statement that production at all of the mines had been suspended as they engaged with unions to manage the situation.

“The mines have implemented contingency plans to continue supplying coal to maintain the functionality of their respective power stations and other customers,” the statement said.

The Matla, Arnot and Grootegeluk mines have adequate stock days of supply but Exxaro said contingency plans were in place to supply customers of the Leeuwpan and Inyada mines.

The strikes began last week as Exxaro announced a 33% drop in full-year earnings for 2012.

The company cited lower coal export prices and volumes for a 23% decline in revenues to R16.1 billion.

The company said the average export price dropped from $US105 per tonne in January 2012 to a low $85/t in November 2012, with Exxaro’s average coal export price for 2012 at $94/t, compared to $118/t in 2011.

Coal revenue was lower at R12.04 million, down 3% on 2011, but overall coal production was stable at 40 million tons per annum.