Westmoreland Coal Co. said Tuesday that it has agreed to buy the coal mining operations of Sherritt International Corp. for about $435 million which will help it expand its operations in Western Canada.

The Englewood, Colo., company said the deal will double its business and make it the sixth largest coal producer in North America.

Westmoreland will acquire seven thermal coal mines in the Canadian provinces of Alberta and Saskatchewan, a 50 percent interest in a carbon plant and a production facility for char, which is used in barbecues.

The deal will increase Westmoreland's annual coal production by about 27 million tons, doubling its current coal production, the company said.

The acquisition is expected to be completed in the first quarter of 2014.

Sherritt, based in Toronto, is shedding its entire coal operations to focus on its nickel and oil business. Sherritt also said Tuesday that it is selling other coal developments to a group led by Altius Minerals of St. John's for 481 million Canadian dollars ($452.7 million).

Westmoreland has coal mining operations in Montana, North Dakota, Texas and Wyoming. It also has a coal-fired power plant in North Carolina.

The company's stock jumped more than 11 percent to $17.42 in morning trading.