Arch Coal Inc.'s Canyon Fuel Co. subsidiary has resumed coal production at a mine in Utah where production had been suspended after a small increase in carbon monoxide levels was detected in a mined-out area.

Production was suspended on April 29. Crews have completed sealing the mined-out area.

About 200,000 tons of coal were produced in the mine during the first quarter of 2010, about 2 percent of Arch's total production, the company said Friday.

Arch, based in St. Louis, is the second largest U.S. coal producer, generating enough coal to fuel 8 percent of the nation's electricity. The company also ships coal to steel companies and international power producers.

Sourced from www.businessweek.com