Chevron

The undisputed leader in energy sector dealmaking is US giant Chevron. In July 2025, it completed a $53 billion acquisition of Hess, emerging victorious in an unprecedented legal battle with its larger rival, Exxon Mobil, over access to one of the largest oil discoveries in recent years. Chevron’s ascent began in 2001, when it acquired Texaco for $39.5 billion, cementing its position among the world’s top energy companies.

Diamondback Energy

Another key player in the oil and gas space is Diamondback Energy. In 2024, the company signed a $26 billion agreement to acquire rival Endeavor Energy Partners, paying in a combination of cash and stock. The deal significantly strengthened Diamondback’s presence in the oil-rich Permian Basin, one of the most coveted shale regions in the United States.

ConocoPhillips

The company emerged from a major merger in 2002, when shareholders of Conoco and Phillips Petroleum, along with the US Federal Trade Commission, approved the $18 billion deal that formed the third-largest oil producer in the United States. In 2006, the company expanded further, buying Burlington Resources for $35.6 billion to gain access to North America’s prolific natural gas basins. Later, in 2020, ConocoPhillips made headlines again by acquiring Concho Resources for $9.7 billion, which became the largest deal in the shale sector at the time.

Exxon Mobil

Another heavyweight in the global oil and gas arena is Exxon Mobil. The company has repeatedly struck major deals over the years. In 2010, Exxon Mobil acquired XTO Energy for $30 billion in stock, securing its position as the leading natural gas producer in the United States. In 2023, Exxon Mobil announced a $59.5 billion all-stock acquisition of Pioneer Natural Resources. The blockbuster deal made it the top operator in the largest oil field in the US.

Equinor and Aker BP

Norway’s energy sector has also produced some of the industry’s biggest transactions. Such mergers often lead to the creation of new corporate giants. In 2007, Norwegian oil company Statoil acquired Norsk Hydro's oil and gas assets in a $30 billion deal. This resulted in the formation of a new energy powerhouse, Equinor. In 2021, another Norwegian firm, Aker BP, acquired Sweden’s Lundin Energy in a cash-and-stock deal worth $13.9 billion, creating Norway’s second-largest oil company.