Exxon deal heats up Canada shale play By: MarketWatch October 17, 2012 at 17:53 PM EDT Exxon Mobil’s $2.9 billion acquisition of Celtic Exploration is Big Oil’s latest move on what is one of the hottest energy plays in North America. Read More >> Related Stocks: Canadian Natural Resources Limited EnCana Corporation Exxon Mobil Macy's Murphy Oil Royal Dutch Shell Plc ADR