Reuters

Exxon Mobil agreed on Wednesday to buy Celtic Exploration for about $3.1 billion in cash and stock, as it sought to expand its presence in the energy-rich shale formations of western Canada.

Under the terms of the deal, Exxon will pay about 24.50 Canadian dollars ($24.92) a share, 35 percent above Celtic’s closing price on Tuesday and 34 percent higher than its 30-day volume-weighted average stock price.

Existing Celtic shareholders will also receive 0.5 of a share in a new company that will be led by Celtic’s current management team.

Investors who own Celtic’s convertible unsecured subordinated debentures will exchange their holdings for common shares in the company, which will then be swapped for the 24.50 dollars and 0.5 of a share in the new company.

The takeover is the latest effort by major oil concerns to tap the oil-rich rock formations of North America, including the province of Alberta, where Celtic is based. In July, the Chinese company Cnooc bid $15 billion for Nexen, a significantly bigger explorer based in Calgary, in large part to get in on the shale boom.

And Exxon has proved interested in finding new shale formations, fortified with drilling technology gained from its $31 billion acquisition of XTO Energy in 2009.

Founded in 2002, Celtic focuses its exploration and production of oil, natural gas and related liquids in west central Alberta, particularly in the Montney and Duvernay shale formations. Its holdings produce about 72 million cubic feet a day of natural gas and 4,000 barrels of crude oil, condensate and other liquids. And it is estimated to hold 128 million oil equivalent barrels of proved and probable reserves.

But Celtic’s shares have fallen nearly 25 percent in the last 12 months, as the company has been hurt by a prolonged trough in natural gas prices.

In the wake of the Nexen deal, however, some analysts speculated that it might be an attractive takeover target for oil companies seeking to gain toeholds in the Alberta shale.

“This acquisition will add significant liquids-rich resources to our existing North American unconventional portfolio,” Andrew Barry, president of Exxon Mobil Canada, said in a statement. “Our financial and technical strength will enable us to maximize resource value by leveraging the experience of Exxon Mobil subsidiary XTO Energy.”

The deal is subject to approval by Celtic shareholders and debenture holders, as well as Canadian government regulators.

Celtic was advised by FirstEnergy Capital, RBC Capital Markets and the law firm Borden Ladner Gervais.