Gold Fields joins Gold One, Anglo Platinum and Kumba Iron Ore, all of which have taken a tough stance against a wave of wildcat strikes that has crippled the mining sector by dismissing thousands of workers.

Gold Fields chief executive Nick Holland said yesterday the company issued the ultimatum after exhausting "all reasonable and lawful alternatives".

This followed a month of paralysis caused by an illegal strike at the company's KDC-West mining complex, near Carletonville, on the West Rand. That strike has since spilled over to Gold Fields' Beatrix and KDC-East mines.

As many as 100000 mineworkerrs joined unprotected strikes in the aftermath of the Marikana shootings, in which 34 miners were killed in August.

Holland said "quite a lot of people are keen to get back to work" but were being prevented from doing so by small bands of "intimidators".

After the collapse of negotiations between the National Union of Mineworkers and the Chamber of Mines earlier this week, Holland believes the ultimatum is the only way "to break the escalating violence on our property".

The mining companies' tough stance against the illegal strikes began two weeks ago when Anglo Platinum dismissed 12500 workers. Gold One followed suit on Monday when it fired 1417 workers at its Ezulwini mine. Operations at the mine have been suspended for at least 30 days.

Kumba not only dismissed 300 workers disrupting its operations at Sishen earlier this week, but also laid charges of extortion, intimidation, theft, trespassing, malicious damage to property and contempt of court against them.

Kumba has a staff complement of 13000 at its Sishen mine. The 300 strikers had seized equipment worth billions of rands and brought operations to a halt at the mine, where workers last year were each paid R500 000 in incentive bonuses and received R15000 in dividends earlier this year and a wage increase a few months ago.

Police removed the striking workers from the mine yesterday morning. The company said it planned to resume operations soon.

But National Union of Mineworkers is worried that dismissals will make things worse.

NUM spokesman Lesiba Seshoka said issuing ultimatums did not take into account the fact that many workers were not taking part in the strikes of their own free will.

"It is very difficult to draw a line between our members and the disruptive forces causing the strikes," he said.

But the "disruptive forces are in charge," he said, threatening NUM members' lives.

Seshoka claimed mining bosses were secretly relishing the opportunity to cut staff.

Holland said, however, that Gold Fields had been more than reasonable in trying to find an amicable solution.

Restructuring, he said, could not be ruled out and it was too early to say whether the strikes had caused permanent damage to the industry.

"We're in uncharted territory," he said.

The longest planned stoppages usually occur over the Christmas break. Operations have now been suspended for nearly a month, stoking fears that production might not return to normal soon.

According to Holland, all Gold Fields workers who report for duty by 2pm tomorrow will benefit from an earlier proposal, tabled by the Chamber of Mines and involving a range of adjustments within the current wage agreements.

The proposal would translate into a 3% wage increase, he said. Holland was, however, quick to say his company was not breaking ranks with the rest of the industry not rewarding illegal behaviour.

"We need to stick to existing wage agreements," he said, adding that it was "quite possible" that other gold mining companies would do the same.

Harmony Gold yesterday said it was still following internal processes to resolve a wildcat strike by 5400 workers at its Kusasalethu operations.

Gold Fields' KDC East mine yesterday applied for a court interdict to have the strike there involving 8500 workers declared illegal.

Holland said he planned to follow the same course at the company's other mines, adding he would soon issue another ultimatum.