According to a report in Wales Online, the Neath Valley drift mine complex officially ended production in December, just before Christmas.
Mine director Karl Picton-Jones told ITV Wales that the mine would be kept open only for care and maintenance, with a staff of 20.
“We could see it open again if the international price of coal picks up,” he said.
Alabama-based Walter Energy did not issue a public statement on the closure.
Vale of Neath regional member of parliament Peter Hain told the Welsh news outlet that the shutdown could cost the local economy as much as £9 ($US14.4) million per year.
Miners’ leader Tyrone O’Sullivan reportedly called the closure a “tragedy for the Welsh coal industry”
“It has been estimated in the Vale of Neath as a whole there are still around 60 million tonnes of top quality anthracite lying underground,” he said. “But here we have a pit closing and men with specialist mining skills lying idle.
“ I say it’s a tragedy for the Welsh coal industry because demand for energy worldwide is huge and we have the skills and resources in Wales to provide top quality coal.”
He told Wales Online that he could not comment specifically on the Aberpergwm closure because he did not know about the conditions at the property.
“But what is needed is a business plan and the will to make a success of the industry in a traditional coal mining area.”
National Union of Mineworkers general secretary Wayne Thomas said that Walter’s plan post-closure could actually be a positive sign.
“Commonsense would tell you if they are operating a care and maintenance [program] they are securing the mine for future operations,” he said.
Walter spokesman Paul Blalock confirmed to ILN in late October that it was in the consultation phase of its closure proposal, during which time the mine’s workers would be off but receiving full pay.
The producer cited the declining demand “that continues to heavily impact the global coal industry” for the decision.
Aberpergwm, near Glynneath, is believed to have a 6.8 million tonne reserve base.
Its main customer, according to Walter’s website, is the Aberthaw power generation plant.
The mine, according to a BBC report, opened in the late 1800s and at its peak in the 1930s employed 1500 workers. It was closed for one year in 1985 then re-opened with a private owner.
Aberpergwm is not far from Walter’s other colliery, Tower. Its other holdings in the region include the Forest quarry opencast and the Dulais Valley Restoration.