BRISTOL, Va. (AP) — Coal producer Alpha Natural Resources Inc. said Thursday that its fourth-quarter loss narrowed, helped by lower charges.

The company's adjusted results and revenue beat Wall Street's expectations. Alpha Natural also said that it expects to substantially lower its selling, general and administrative expense in 2013.

Shares rose more than 5 percent in premarket trading.

Alpha Natural lost $127.6 million, or 58 cents per share, for the period ended Dec. 31. That compares with a loss of $792.9 million, or $3.62 per share, a year earlier.

Stripping out impairment and restructuring charges and other items, it lost 19 cents per share.

Analysts predicted a loss of 52 cents per share, according to a FactSet survey.

The company said it had $228 million in impairment and restructuring charges in the current quarter. The prior-year period included $802 million in impairment charges.

Revenue dropped 25 percent to $1.56 billion from $2.07 billion as coal revenues declined. This topped Wall Street's forecast of $1.55 billion.

Alpha Natural's stock climbed 44 cents, or 5.2 percent, to $8.93 in morning trading.

The company said that both total revenue and coal revenues were hurt by lower coal shipment volumes and lower average realizations for metallurgical and Eastern steam coal.

Metallurgical coal shipments fell to 4.9 million tons from 5.3 million tons a year ago.

Alpha Natural's full-year loss widened to $2.44 billion, or $11.06 per share, from $730.5 million, or $4.06 per share, in the prior year. Annual revenue fell 2 percent to $6.97 billion from $7.12 billion.