By accepting management's offer, pitmen at Tower colliery near Aberdare forfeited up to pounds 9,000 a head in enhanced redundancy payments.
British Coal has promised to keep production going until the mine is offered for sale under privatisation at the end of the year.
Edward Hindmarsh, BC's head of operations, said management had reconsidered its closure plan 'in the light of the strength of the NUM's feeling and the union's optimism for the future of the colliery'.
However, one senior BC source predicted problems in the pit because the National Union of Mineworkers was the only union out of five to reject the present redundancy package and vote to keep the colliery open. 'We were trying to do the right thing by the miners in the pit. Now they will have to take their chances under privatisation with much reduced redundancy payments. The story is not over yet, there will almost certainly be problems next week.'
Mr Hindmarsh said 'normal operations' - including development work which stopped on 7 April - would be resumed immediately. Miners would be paid normal basic rates plus locally agreed incentives and bonuses.
The announcement came as the Labour MP Ann Clwyd emerged from the pit after spending 27 hours in an underground 'sit-in' protest. The 57-year-old MP for Cynon Valley, her face covered in coal dust and wearing a miner's helmet, was cheered by miners as she celebrated 'victory' in the campaign to save the pit.
Earlier, miners vowed at a two-hour meeting at a nearby miners' institute hall that they would not bow to British Coal pressure to shut the pit, which has made pounds 28m profit in the last three years.