The country's coal sector has had a turbulent year so far with a month-long strike at the biggest miner Cerrejon in February and another which began on July 23 and is still continuing at smaller rival Drummond.
Colombia, the world's No. 4 coal exporter, cut its target for 2013 coal production to 94 million tonnes earlier this year as a result of turmoil in the sector. As well as the strikes, the environmental regulator ANLA temporarily closed down a key mine-to-port railway and halted ship loading by Drummond.
Royalties paid to the government by mining companies tumbled 26 percent in the first half of the year compared to the same period a year earlier, to 513 billion pesos ($272.5 million) down from 689 million pesos, the agency said.
Though Colombia is not a major coal producer in absolute terms, it is one of the biggest players in the sea-borne or export coal trade since the world's largest coal producers like the United States and China, consume most of their own output.