BOGOTA, April 14 (Reuters) - Drummond, Colombia's second-biggest coal producer, has started talks with three small workers' unions to seek agreement on labor conditions and benefits, though it has been unable to meet with the main coal syndicate, the company said on Thursday.
Some 4,905 Drummond workers are affiliated with five unions.
Drummond said in a statement it began formal negotiations with Sintradrummond, Agretritrenes and Sintramineros on Wednesday and that the talks will run for 20 days.
So far, the Alabama-based company has been unable to initiate discussions with the biggest union, Sintramienergetica, and the smaller Sintradem.
Sintramienergetica, with 2,300 affiliates, held a strike in 2013 that lasted 53 days and paralyzed production and exports of Drummond coal.
Drummond produced 25.8 million tonnes of coal in 2015, 30 percent of Colombia's total 85.5 million tonnes of output.
Apart from Drummond, the coal sector in Colombia is dominated by Cerrejon, a joint venture between Australia-based BHP Billiton Ltd, London- and Johannesburg-based Anglo American Plc and Swiss-based Glencore Xstrata. Prodeco, a unit of Glencore Xstrata is also present.
Last month, Cerrejon and unionized workers reached an accord to avoid a strike. (Reporting by Luis Jaime Acosta; Writing by Helen Murphy; Editing by Alan Crosby)