Duane Feagley, in an interview with Platts, said he did not have precise numbers to support his assertion of a production decline, but anecdotal evidence from trade groups showed that anthracite coal production and prices were down in Pennsylvania during the first five months of 2013.

According to the US Energy Information Administration, Pennsylvania produced 2.13 million tons of the US anthracite total of 2.35Mt last year.

Feagley said production so far this year had been hindered by increasing competition overseas and disappointing demand from US steel producers. It was unclear whether the state would hit the 2 million ton mark this year, he said.

One small anthracite producer, whom he declined to identify, had witnessed a 30% drop in production so far in 2013, he told Platts.

The EIA said in its latest weekly data report that 885,000 tons of anthracit coal had been produced so far this year, down 1.5% from the 898,000 tons of anthracite produced this time last year, based on railroad car loading data.

Platts cites two Pennsylvanian producers, Blaschak Coal and Atlantic Coal, who both attribute a decline in the market to “aggressive pricing by one particular producer".

Blaschak chief Greg Driscoll said some of the state's anthracite was selling for less than $100 a ton, confirming that was not the norm and exports had been “real slow”

According to the EIA’s data from 2011 (the most recent available), the average sale price of a ton of Pennsylvanian anthracite was $75.70.

Atlantic told Platts it expected the situation to be "short-term in nature", with a price recovery expected by the fall.

Driscoll is not so sure.

"Demand is down a little below budget, and we sort of expect that for the remainder of the year," he said.