Pertamina is a state-owned company operating in Indonesia’s oil and gas sector. The company’s undertakings range from upstream activities such as exploration and extraction, processing, to downstream activities such as trading and distribution. Pertamina is also a holding company to dozens of subsidiaries in diverse sectors.

Sele Energy is an Indonesian group of companies focused on the exploration and production of crude oil and natural gas. The group holds concessions for the Merangin Dua Block and the Belida Block in South Sumatra, and the Blora Block in Central Java.

Elnusa Tbk is a subsidiary of state-owned oil and gas company Pertamina. The company engages in providing comprehensive supporting services for upstream and downstream oil and gas operations, including seismic data acquisition and processing, oilfield drilling and maintenance services, asset and data management, etc. Elnusa is a publicly traded company and a parent company to eight main subsidiaries.

Medco Energi Internasional Tbk is an Indonesia-based publicly-traded company primarily engaged in the oil and gas sector. The company carries out exploration, development and production activities in a number of oil and gas blocks in Indonesia, as well as other countries such as USA, Tunisia, Libya, Oman, Yemen and Papua New Guinea; directly or through subsidiaries. Other business operations include gas distribution, coal mining and workover drilling activities. Medco Energi Internasional is a parent company to PT Medco E&P Indonesia, Medco Strait Services Pte Ltd, PT Exspan Petrogas Intranusa, and a number of other subsidiaries.

Ratu Prabu Energi Tbk is a holding company for various subsidiaries engaged in the oil and gas sector, and the property sector. Among its subsidiaries are PT Lekom Maras in mining services and property, PT Lekom Maras Pangabuan in petroleum extraction, PT Bangadua Petroleum in oil and gas, and PT Ratu Prabu Tiga in property development, rental and management.

Rukun Raharja Tbk is an Indonesia-based publicly-traded company primarily engaged in the energy sector. The company's business activities include the distribution of natural gas and liquefied petroleum gas as well as the transmission, transportation and compression of gas with customers which include industrial and commercial manufacturers and power plants. Rukun Raharja is a parent company to PT Cahya Saguna Niketana, PT Triguna Internusa Pratama and PT Panji Raya Alamindo.

Surya Esa Perkasa Tbk is an Indonesia-based company engaged in liquefied petroleum gas refining in Indonesia. The company owns and operates facilities in Palembang, South Sumatra, for refining and processing natural gas to produce propane, butane and condensate. Surya Esa Perkasa is a publicly traded company with PT Trinugraha Akraya Sejahtera and PT Ramaduta Teltaka as its largest shareholders.