Tourmaline Oil Corp. is beefing up its North Montney Shale holdings with the C$1.1 billion ($900 million) purchase of privately held Black Swan Energy Ltd., a deal that could position supplies for the Canadian liquefied natural gas (LNG) market. 

Tourmaline said Friday the purchase was an “important component” of its ongoing consolidation strategy in the North Montney region of northeastern British Columbia (BC), which is expected to supply Western Canadian LNG export terminals. 

Tourmaline expects “the North Montney to be the primary growth driver in the entire Western Canadian Sedimentary Basin for the next decade.”

The company said it would acquire Black Swan for 26 million common shares and assumption of up to C$350 million ($288 million) of net debt. In exchange,...