The company also tripled its income from operations to $169 million during the period.

Arch chairman Steven Leer also pointed to trading and asset optimisation for its success over the three months to June.

“Our diverse asset base helped the company overcome the impact of weather-related challenges at our Powder River Basin operations during the quarter just ended," Leer said.

Arch president and chief operations officer John Eaves said the company benefited from record pricing while it continued to focus on cost control.

“Our mining complexes delivered strong performances in the quarter, driven by our operations in Central Appalachia – particularly Mountain Laurel – as well as an expanded contribution from our operations in the Western Bituminous region,” said Eaves.

“Additionally, our Powder River Basin operations achieved a solid performance in the second quarter while persevering through adverse weather conditions and rail challenges."

The heavy rainfall hit Powder River Basin production to the tune of 1 million tons in lost production.

In the Western Bituminous region, Arch’s second-quarter 2008 sales volume rose by 600,000t compared with the first quarter, driven by increased shipments from the West Elk mine in Colorado.

In Central Appalachia, the company’s second-quarter 2008 sales volume increased more than 11% compared with the first quarter, primarily driven by higher production rates at several of Arch's operations in the region.

As with many of its peers, Arch will take advantage of record spot prices by selectively signing contracts while continuing to maintain significant exposure to coal markets.

Based on Arch's positive outlook on the future direction of coal markets, Arch raised its 2008 guidance to adjusted EBITDA of $767–853 million and sales volumes of 133–137Mt.

“We are on track to deliver our best earnings performance in company history during 2008," Leer said.