The strike ended more than three months of negotiations during which Glencore, Anglo American and Exxaro, via the Chamber of Mines, had raised their offer to raise wages by up to 8.5% for the lowest-paid workers from 8%, when inflation locally is at 4.6%.

The union had demanded a 14% increase for its miners, artisans and officials and a 13-14% increase – or R1000 ($A10.34) for the sector’s lowest-paid workers.

"We took the decision to strike because we reached a deadlock," National Union of Mineworkers spokesman Livhuwani Mammburu told AFP.

"It will continue indefinitely until the two parties can come together and solve their differences.

“Striking is the only way for the workers to express their dissatisfaction with these offers.”

It’s the last thing Glencore needs after its London shares plummeted 29% last week triggering a route that wiped some $A50 billion from the Australian Securities Exchange alone before the Swiss commodities trader staged a recovery.

Glencore announced in August it was putting its Optimum coal mine into a form of bankruptcy protection as it seeks to restructure the company, citing “unsustainable financial hardship”

The mine supplies state-owned utility Eskom.

Chamber of Mines data shows the coal sector employs about 90,000 people.