Talks between the Sintramienergetica union and Drummond officials had been ongoing for weeks, however, a union spokesman confirmed the unlimited stoppage began late Tuesday night.

“It is indefinite,” union vice president Edgar Munoz told Reuters.

“Unfortunately the company wouldn't budge. It's a pity.”

He added that the union, which represented about 10,000 Drummond workers in the South American country, was open to continuing talking and could suspend the strike should Drummond up its game.

A Drummond spokeswoman told the news service that all production had stopped and no shipments were being made at the producer’s sea port, as crews there are also part of the walkoff.

Drummond has not commented directly on details of the strike itself.

Coal is one of Colombia’s largest export commodities, and Drummond produced about one-third of the country’s output last year – about 26 million tonnes – from its two mines.

The strike, if prolonged, could have a ripple effect in terms of pricing and demand by those countries which purchase its tonnage. Additionally, the walkoff has come at a time when many purchasers are making deals for winter supplies, adding to the supply and demand crunch.

The union wants a 9% wage increase along with incremental increases in coming years tied to inflation rates. Drummond’s latest offer was 4.75%, along with a one-time bonus of about $3700.

Neither has budged from their positions.

“We are convinced that it is an excellent proposal, especially taking into account current low prices for coal in the industry and those expected in coming years,” Drummond told Reuters.

This week, Munoz said the producer’s offer was close to what its members would accept, but the workers want a fixed monthly base plus an hourly wage rather than just by-the-hour wages. So far, Drummond has refused the demand.

Sintramienergetica workers are also looking for some security for 400 individuals at

Drummond’s port facility, who are targeted for furlough once the company starts loading coal by conveyor belt in 2014.

While the union has demanded all workers be offered transfers to other Drummond positions, the Alabama-based miner has promised to keep only 70% of the facility’s payroll.

As the action rolls out, Munoz told Reuters that workers were camping out in front of Drummond's installations and will remain there during the stoppage.

“The strike has begun calmly and peacefully,” he said.

It is not the first strike for the coal-rich country in 2013. In February hundreds took part in a month-long strike at the Cerrejon complex for a similar cause.

Colombia is South America’s largest coal producing nation.