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Supasit Boonsanong is a partner in Tilleke & Gibbins’ corporate and commercial department and head of the firm’s regional Energy industry group. His in-depth legal and energy industry knowledge has earned him recognition as a leading Projects and Energy lawyer by Chambers Asia-Pacific (2023-) and a leading Project Development lawyer by IFLR 1000 (2024-).

Supasit specializes in complex cross-border energy industry transactions, including project finance and M&As, and renewable, oil, gas, and petrochemical industry operations. He advises leading energy and natural resource companies on project development, joint ventures, licensing, supply, construction, and financing agreements. He also specializes in negotiating engineering, procurement, and construction (EPC) contracts for process plants, conventional power plants, tank farms, and renewable energy installations (solar, wind, hydro, biomass, and waste conversion).

Supasit is chief of the legal team advising Thai government authorities on legislative amendments to the country’s petroleum laws, including drafting regulations, models of petroleum production sharing contracts, and risk service contracts under the Petroleum Act. He also teaches petroleum law and investment law at the Faculty of Law, Chulalongkorn University.

Supasit has over 20 years of experience at respected international law firms in Bangkok and over 15 years as general counsel to Thailand’s National Petrochemical Company.


  • Advised a Thai storage tank services company on bidding preparation and negotiation of project documents for two EEC megaprojects for ports. The projects were valued at THB 30 billion each.
  • Advised a SET-listed electricity distribution company in connection with its proposed investment in a rooftop solar company.
  • Advised a publicly listed Thai printing company in connection with its acquisition of the printing business of one of Thailand’s largest media companies.
  • Advised a SET-listed industrial park company, as the borrower, in connection with a THB 1.625 billion loan arrangement from a Singaporean bank.
  • Acted as legal advisor for drafting the Department of Mineral Fuels’ regulations and model agreements on product-sharing agreements and risk service contracts, and assisted with decommissioning a national oil company.
  • Advised project shareholders from Thailand and Korea on cross-border project development and project financing for design, development, construction, operation and maintenance of a major “greenfield” 65 MW hydroelectric plant in Laos.
  • Advised a major Thai energy company on cross-border investment in a leading international retail/wholesale group with businesses across Europe.
  • Advised a Thai small power producer (SPP) on the development and financing of a major gas-fired, combined-cycle power plant in Thailand, including advice on structuring the EPC contract and drafting all other project agreements.
  • Conducted due diligence on the rehabilitation process of a state-owned telecommunications company.
ABOUT Supasit








    LLM, Center for Petroleum Law and Mineral Studies, University of Dundee, U.K.

    LLB, Chulalongkorn University


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