Royal Dutch Shell agreed to buy smaller rival BG Group for 47 billion pounds ($70.2 billion) in the first major energy industry merger in more than a decade, closing the gap on market leader ExxonMobil after a plunge in prices.

Anglo-Dutch Shell will pay a mix of cash and shares that values each BG share at around 1,350 pence, the companies said. This is a hefty premium of around 52% to the 90-day trading average for BG, setting the bar high for any potential counter-bid by a company like Exxon, which has said it would also use the oil markets downturn to expand. The third-biggest oil and gas deal ever by enterprise value will bring Shell assets in Brazil, East Africa, Australia, Kazakhstan and Egypt, including some of the world’s most ambitious liquefied natural gas (LNG) projects. Shell is already the world’s leading LNG company and it would get BG’s capacity in LNG logistics—complex infrastructure that includes terminals, pipelines, specialized tankers, rigs, super coolers, regasification facilities and storage points.