Deal will close in the second quarter of 2024.: A major American natural gas company is acquiring a smaller rival, extending a wave of consolidation sweeping over the American oil and gas industry. Chesapeake Energy, one of the country’s largest natural gas producers, is buying Southwestern Energy in a $7.4 billion all-stock deal, the companies announced Thursday. The deal follows ExxonMobil’s acquisition of Pioneer Natural Resources and Chevron’s purchase of Hess in late 2023.