Exxon Mobil Corporation said Wednesday that its Canadian affiliates will acquire Calgary-based Celtic Exploration Ltd. in a deal worth $3.2 billion, including assumed debt.

The deal would give Exxon Mobil Canada ownership of more than 650,000 net acres in multiple shale plays spread across an oil-rich stretch of western Canada that is increasingly being targeted by energy companies around the world. Among the flurry of deals centered in the region: this summer’s $15.1 billion purchase of Canadian oil and gas company Nexen Inc. by China National Offshore Oil Corporation (CNOOC)—a megadeal that is awaiting government approval.