For the period ended September 30, the Ohio-based company recorded a net loss of $US5.1 million, compared to a net loss of $3 million for the third quarter of 2012.

Production was approximately 40,000 tonnes less than expected, which officials said was mainly due to an August overburden collapse at one of its operations that trapped a highwall miner and rendered it inoperable for a period of multiple weeks.

Third-quarter cash margins were $6.40/t, down 21.9% or $1.79/t over the third quarter of 2012, when it was $8.19/t.

Coal sales revenues were up 2.6% year on year to $50.74/t, but that total was offset by a 7.6% rise in cash costs of coal sales to $44.34/t stemming from the lower production.

“We had a challenging third quarter as the production from one of our two highwall miners was disrupted for close to a month," Oxford president and chief executive officer Charles Ungurean said.

“Fortunately, we were able to expeditiously replace the highwall miner and resume production.

“Looking forward, we remain committed to successfully navigating through this market downturn by closely managing our capital expenditures and liquidity, and leveraging the assets redeployed from the Illinois Basin to our Northern Appalachian operations."

Looking at the remainder of the year, Oxford confirmed it is fully committed and priced for its volumes. It attributed the achievement to the strength of its long-term customer relationships as well as the strategic importance in its core region.

For next year, the producer already has 5Mt of sales committed, of which 3.3Mt are priced and 1.7Mt are unpriced.

“Oxford is focused on its core Northern Appalachian operations,” the thermal miner, also the largest producer of surface-mined coal in Ohio, said.

“Continued rationalisation of the partnership's Illinois Basin operations has allowed for the transfer of excess equipment to the Northern Appalachian mines, which has reduced capital spending.

“Based on current market conditions, the partnership expects to idle all production at its Illinois Basin operations by the end of 2013 and finish redeploying equipment during the first quarter of 2014.”

The company updated its guidance for whole-year 2013 based on its current industry outlook, indicating it expects to produce between 6.1Mt and 6.3Mt and sell between 6.6Mt and 6.8mt of thermal coal at an average selling price of between $50.75/t and $51.25/t and anticipated average cost of $43.75/t to $44.25/t.