Ratthakarn is a partner in the dispute resolution group.

Ratthakarn has served as lead trial lawyer in high profile, multi-jurisdictional cases for over three decades. His clients range from governments to multinational corporations and major Thai companies and conglomerates. He specialises in international trade, commercial disputes and business crime, with a particular focus on the energy, construction and insurance sectors.

Ratthakarn has extensive experience in court litigation and arbitration, acting as both arbitrator and counsel in cases under various arbitration rules including the PCA, ICC, SIAC, LCIA, KCAB, TAI, THAC and OIC, as well as ad hoc arbitrations under UNCITRAL Rules.

He has been recognised as a leading lawyer for dispute resolution and international arbitration in Thailand by the legal directories Chambers Asia Pacific and Legal 500 Asia Pacific for over 16 consecutive years. In 2026, the latter highlighted that “amongst the team, Ratthakarn Boonnua stands out for his strategic insight and ability to manage complex issues with clarity and confidence”.

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  • Representing Kingdom of Thailand and the Ministry of Energy in multi-billion-dollar arbitration proceedings relating to decommissioning disputes with oil major concessionaries concerning assets in the Gulf of Thailand.
  • Representing Kingdom of Thailand and the Ministry of Energy in an investment treaty arbitration brought by an Australian oil company concerning the breach of Thailand-Australia Free Trade Agreement (TAFTA).
  • Successfully representing PTT Public Company Limited in a multi-million-dollar dispute involving claims and counterclaims relating to the procurement of a CTRM System and securing a landmark victory in the UK Supreme Court.
  • Representing a Thai national energy company on EPC contracts for its Gas Separation Plant Project and the Interconnection Pipeline Project and in correction with complex construction disputes arising from these projects. This includes advising on strategy for the preparation of a potential litigation initiated by a Chinese UJV counterparty.
  • Representing a major Thai oil and gas corporation in multi-million-dollar arbitrations brought by its contractor at the Thai Arbitration Institute (TAI). The disputes arose from the early termination of four agreements for the supply of OCTG products to support offshore development in the Gulf of Thailand.
  • Successfully representing a subsidiary of a major Thai oil and gas corporation in a THB350m arbitration brought by its contractor at the Thai Arbitration Institute. The claim arose from the early termination of service agreements for the operation of a natural gas wellhead platform in the Gulf of Thailand.
  • Successfully representing AGC Automotive (Thailand) Co., Ltd. in a THB95m Thai civil court claim for breach of contract for the sale and installation of solar rooftops for a clean energy project in Thailand.
  • Representing Bangchak Corporation Public Company Limited in a multi-million-Thai Baht claim brought against them in the Thai Courts by a distributor of lubricant products, achieving a successful outcome in the Supreme Court.
  • Successfully representing PTT Public Company Limited in a UK Supreme Court hearing relating to a multi-million-dollar dispute between PTT and Triple Point Technology, Inc.
  • Advising Ford Motor Company and its Thai affiliates on contingent business interruption claims arising out of the 2011 Thai floods against its insurer in Thai courts.
  • Advising a Dutch multinational dairy company on complex appeal proceedings in cases brought by a major British food company in the Thai courts, with circa US$62m in dispute.

Education

  1. 1999 · Institute of Maritime Law, Faculty of Law, University of Southampton, UK Certificate, Maritime Law Short Course
  2. 1993 · Qualified to practice (First Class licence)
  3. 1992 · Thammasat University, Bangkok, Thailand LL.B

memberships & associations

  1. Registered Foreign Lawyer, Solicitors Regulation Authority, UK
  2. Associate member, The Chartered Institute of Arbitrators, UK
  3. Member of the Arbitration Committee, ICC Thailand
  4. Member of the Thai Bar Association
  5. Member of the Lawyers Council of Thailand