Terms of the preliminary wage accord will be presented to workers early this week, with the negotiating committee reaching an agreement with management in the early hours of Monday morning.

Cerrejon is Colombia’s biggest coal mine, producing 100,000 tons of coal a day. It has produced no coal since the strike began on February 7.

"After arduous negotiations ... the Sintracarbon (union) commission and Cerrejon have built agreements to govern the 2013-14 collective bargaining agreement, if they are approved by Sintracarbon's members," the union said in a statement.

Sintracarbon is demanding a pay increase and better health benefits for workers, of which it represents about 5000.

Negotiations have broken down many times, but this will be the first time a wage accord is presented to workers.

The strike, combined with an export ban at a complex owned by Drummond Co, has had a major impact on the export value of Colombian coal.

Javier Garcia, head of corporate mining for the Ministry of Mining and Energy, told Bloomberg Friday that the shutdowns were costing Colombia 192,000 tons of exports per day, affecting 79% of the country's output.

Drummond's shipping licence was suspended by the government after the Alabama-based coal giant dumped about 300 tons of coal into the Caribbean Sea after a barge accident. The licence was reinstated last Friday.

Cerrejon is owned by Xstrata, Anglo American and BHP Billiton.

Colombia is the world’s fourth-largest coal exporter. It produced 87 million metric tons in 2011, falling short of a 100Mt goal, in part because of a 25-day coal railway strike that forced output target cutbacks.