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Work +66 2 646 1888
Fax +66 2 646 1919
Bangkok, Vientiane, Yangon
Siam Premier International Law Office Limited, Techatat Udomsiri, Bangkok, THAILAND

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Techatat Udomsiri

Work +66 2646 1888 ext: 1006
Siam Premier International Law Office Limited

Work Department

Partner – LLB (1st Class Honours), Barrister-at-Law, MBA


Specialises in: Litigation & Dispute Resolution


As a partner of Siam Premier, Techatat Udomsiri’s special area of practice is litigation & dispute resolution. He practices in various areas of civil and commercial litigation, criminal law, labour relations litigation, bankruptcy and arbitration. Techatat’s work in the past and present for leading international and Thai banks such as Bank of America, European Asian Bank, Bangkok Bank, Banque Paribas, United Overseas Bank (UOB), Overseas Union Bank (OUB), Sumitomo and Sakura Bank, Oversea Chinese Banking Corporation (OCBC) and International Finance Corporation (IFC) of World Bank, includes acting in debt recovery claims under loan and security documents and restructuring and insolvency cases. Techatat has also acted for companies including Siam Cement Group, Harrods, Seiko and Planet Hollywood in intellectual property claims and dispute resolution procedures. He also has extensive experience in international trade disputes and contractual claims by representing Mitsui & Co., Mitsui (Thailand) Co., Ltd., Banpu Plc., Asia Partnership Fund, Caltex Oil (Thailand) Ltd., Asia Pacific Breweries Singapore Pte Ltd., etc., arbitration proceedings and enforcements by representing Thai Plastic and Chemicals Plc. (TPC), labour disputes by representing Qantas Airways, Dusit Thani Hotel, Amway (Thailand), Dao Chemical (Thailand), etc. Recently Techatat has been involved in representing Mitsubishi Electric Corp. in litigation surrounding breach of contract during the construction of Blueline Underground. Regarding the criminal cases, he has handled various cases for many local and foreign clients (natural and juristic persons).


He was admitted as a Barrister-at-Law in 1979 and is a member of the Thai Bar Association and the Lawyers Council of Thailand.


Dispute resolution

Within: Dispute resolution

Siam Premier International Law Office Limited's sizeable disputes department was further strengthened by the arrival of a team of lawyers including senior consultant Sumit Masrungson from Chandler MHM Limited. Specialising in contentious employment matters, Masrungson regularly represents companies in the Thai labour courts and in pre-litigation actions. In 2017 and 2018, the dispute resolution team saw an uptick in administrative proceedings and construction litigation, the latter of which is an area of particular expertise. In one highlight, a multi-disciplinary team including litigator Techatat Udomsiri acted for the plaintiff in relation to an administrative law claim concerning a construction contract with a Thai state enterprise. Aviation, real estate and energy are also among the team's sector strengths. In the energy space, Kong Suriyamontol represented PTTEP in a contract dispute concerning a certain natural gas project, which involved court litigation and arbitral proceedings. Suriyamontol also took the lead role in defending a company in the metals and mining sector in large-scale environmental litigation. Additional contacts include senior litigator Noppramart Thammateeradaycho, who has a strong maritime and insurance litigation and arbitration practice.

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