BP p.l.c. engages in the energy business worldwide.
John Wood Group PLC, together with its subsidiaries, provides project management, engineering, consulting, and technical services to energy and built environment worldwide.
Energean Oil & Gas plc operates as an independent oil and gas exploration and production company.
Petrofac Limited, an oilfield service company, provides services to the oil and gas production and processing industry worldwide.
Cairn Energy PLC operates as an independent oil and gas exploration, development, and production company.
Diversified Gas & Oil PLC operates as an independent owner and operator of producing natural gas and oil wells primarily in the Appalachian Basin of the United States.
Tullow Oil plc engages in the oil and gas exploration, development, and production activities primarily in Africa and South America.
Eland Oil & Gas PLC, together with its subsidiaries, engages in development, exploration, and production of oil and gas properties in West Africa.
Seplat Petroleum Development Company Plc, an oil and gas company, explores for, develops, and produces oil and gas in Nigeria.
Indus Gas Limited, together with its subsidiaries, operates as an oil and gas exploration and development company in India.
Genel Energy plc, through its subsidiaries, engages in the oil and gas exploration and production activities.
Hunting PLC, together with its subsidiaries, manufactures and distributes tools and components for the upstream oil and gas industry worldwide.
Phoenix Global Resources plc operates as an independent oil and gas exploration and production company in Argentina.
Hurricane Energy plc, together with its subsidiaries, discovers, appraises, and develops oil from fractured basement reservoirs.
Serica Energy plc, an upstream oil and gas company, engages in the identification, acquisition, exploration, and exploitation of oil and gas reserves.
Amerisur Resources plc engages in the exploration and production of oil and gas assets.
