(Bloomberg) -- Sibanye Gold Ltd. faces the prospect of a strike in South Africa after the country’s Association of Mineworkers and Construction Union demanded a better wage offer for its members.

“AMCU has decided to go on strike,” the union said on its unverified Twitter feed. Sibanye will be given 48 hours to come back with a better offer, it said.

AMCU received permission to strike at Sibanye in September after talks deadlocked. On Nov. 14, the gold mining company signed three-year wage agreements with a trio of other South African unions, ending months of negotiations that started in July.

It raised the basic wage for most categories of surface and underground employees by 700 rand ($50.03) a month in each of the first two years and by 825 rand in the third, while the housing allowance and medical benefits were also increased.

Sibanye shares have slumped 39 percent this year, compared with a 14 percent decline on the FTSE/JSE Africa Gold Mining Index.

To contact the reporter on this story: Paul Burkhardt in Johannesburg at pburkhardt@bloomberg.net

To contact the editors responsible for this story: Alastair Reed at areed12@bloomberg.net, Paul Jarvis, John Bowker

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