Fenoco's shareholders are among the biggest coal exporters in Colombia, and the railway was hit this year by a five-week labor strike, which shut off more than half of shipments from the world's No. 4 coal exporter.
The Regional Autonomous Corporation of Cesar, which oversees environmental issues and whose decisions are binding, said it ordered Fenoco to stop transport runs in areas where it passed less than 100 meters from communities between the hours of 2230 and 0430.
"This preventive measure will be lifted once the causes are found to have disappeared," said the resolution, dated Dec. 10.
It was not clear what the impact of the decision has been or whether Fenoco could or would appeal it, but the rail line crosses several populated areas, including Bosconia.
Fenoco, which generally runs trains around the clock, did not immediately respond to requests for comment.
A union leader said he had not yet seen the decree.
In the past, companies have gone to the environmental ministry to request that it revise decisions by the Regional Autonomous Corporations.
Shareholders in Fenoco include Glencore International Plc's Prodeco unit, Drummond International and Goldman Sachs Group Inc's Colombian units.
Daily coal supply to ports served by Fenoco is up to 160,000 tons and the train has an annual capacity of about 42 million tons, according to the company.
In August, Fenoco workers ended the 25-day strike, which had paralyzed exports and forced a cut in production estimates for this year.
Colombia's coal industry is dominated by big thermal producers with their own port and rail facilities such as Glencore, Drummond and Cerrejon, which is owned equally by BHP Billiton, Anglo American and Xstrata. (Reuters)