Matthieu Gregoire

Matthieu graduated from the University of Cambridge in 2008, completed his masters at Sciences Po Paris in 2010 and his LLM at Georgetown, D.C in 2010.  He was called to the New York Bar in 2011 during his time at an international law firm in Paris before being called to the Bar in England and Wales in 2013.  Since 2015, he has been Adjunct Professor of International Commercial Arbitration at Pepperdine University and appointed to the Attorney General’s PIL C Panel in 2017 whilst studying for the Paris Bar.

Matthieu specialises in commercial litigation, international commercial arbitration, and investor-state arbitrations.  He is recommended in Chambers and Partners and the Legal 500 as a leading junior  in international arbitration, public international law, commercial litigation and was a nominee in the Legal 500 Bar Awards for International Arbitration Junior of the Year 2022.

Matthieu’s has acted for governments, corporations and individuals in oil and gas, renewable energy, mining, manufacturing and finance disputes.  Many of which have included issues of civil fraud. Matthieu has recently acted in the following arbitrations:

  • Acted and/or advised in matters before all levels of English courts, in commercial and international disputes.
  • Acted and/or advised in numerous investment treaty arbitrations pursuant to a wide array of investment treaties with issues relating to most major legal sectors.  With exceptional experience of ICSID, SCC, UNCITRAL and ad hoc rules.  Matthieu’s recent experience also includes disputes under the OIC Investment Agreement and intra-EU BITs.
  • Acted and/or advised in numerous commercial arbitrations, with experience of  ad-hoc and institutional rules (ICC, LCIA, SCC, UNCITRAL), across a range of sectors and industries.  Many of which included issues relating to  a variety of international governing laws.
  • Advised States, non-governmental organisations, private commercial entities and private individuals on a diversity of commercial, arbitration and public international law issues, including treaty interpretation, WTO/Trade law, and implications of Brexit.

Arbitration (including arbitration-related court applications)

Matthieu practices investment treaty arbitration and international commercial arbitration, often in proceedings with an English law element (whether as the governing law of the contract or the proceedings), either led or often as sole counsel.  Matthieu also appears in arbitration-related proceedings.

Matthieu has built on his experience as an attorney in the Paris office of Cleary Gottlieb, Steen & Hamilton, where he acted in investment treaty and commercial arbitrations, and as a consultant for the World Bank, where he advised States and Chambers of Commerce on the creation of arbitration and/or mediation laws or centres and the reform of investment law.

Matthieu combines his practice with the role of adjunct professor of law (international commercial arbitration) at Pepperdine Law School, University of Malibu (London Campus). He publishes widely in the area and regularly contributes to conferences or talks.

Featured international arbitration cases include:

  • LCIA Arbitration (2023-ongoing): acting for a commodities trader in a dispute over the delivery of product (details not public);
  • ICC Arbitration (2023): acting for a respondent state-owned entity under the ICC emergency arbitrator procedure (details not public);
  • LCIA Arbitration (2023-ongoing): acting for the respondent in a dispute over a joint venture in the Middle East (details not public);
  • A v B (2023): acting as sole counsel for a global food corporation in successfully obtaining the dismissal of a challenge to an arbitral award (details not public);
  • UNCITRAL Arbitration (2022-ongoing): Acting for the Respondent state-owned West African electricity company in a claim said to be worth USD 100 million arising out of an energy project (including cross-examination of fact, technical and quantum expert witnesses) (details not public);
  • A v B (2022): acting as sole counsel for a West African State in proceedings before the Commercial Court arising out of an arbitral award rendered against it;
  • Skubenko and others v North Macedonia, ICSID Case No. Arb/19/9; Acting for the Claimants in Skubenko and others v North Macedonia, ICSID Case Arb/19/9, in a dispute over a copper mining complex in North Macedonia, under the Ukraine-North Macedonia BIT;
  • Al-Tuwairqi v Pakistan (UNCITRAL); Acting for the Claimants in Al-Tuwairqi v Pakistan, a dispute over a steel manufacturing plant in Karachi, under the OIC Investment Treaty (under the UNCITRAL Rules);
  • KLS Energy Lanka Sdn. Bhd v. Sri Lanka ICSID Case No. ARB/18/13: Acting for a South Asian State in a claim brought by investors arising out of a renewable power plant;
  • LCIA Arbitration (2021): acting on behalf of an insurer in a dispute arising out of a commodities project in Southern Africa.  The case involved allegations of fraud and was said to be worth over USD 40 million (details not public);
  • ICC Arbitration (2021): Acting for the Respondent in an ICC arbitration arising out of the largest petrochemicals plant in the world (details not public);
  • OIC Arbitration (2021-2022): Acting for the Claimants in an OIC Investment Agreement arbitration against a middle-eastern state (details not public);
  • ICC Arbitration (2020): Acting for the Respondent in an ICC arbitration said to be worth over USD $500 million arising out of a tolling agreement relating to a liquified natural gas plant project in the Middle East (details not public);
  • LCIA Arbitration (2018-2019)  – Investor vs East African State; Acting for a Claimant in an LCIA Arbitration arising out of an energy project in an East African State (details not public).
  • LCIA Arbitration (2017) – Joint Venture Dispute; Acting for the Respondent in an LCIA Arbitration arising out of a joint venture in a CIS State involving jurisdiction issues, alleged minority oppression and questions of interpretation of the joint venture agreement.
  • ICC Arbitration (2017) – West African Construction Project; Acting for the Respondent in an ICC Arbitration arising out of an infrastructure project in West Africa (details not public).
  • Micula & Others v Romania [2017] EWHC 31 (Comm); Acting as junior counsel for the First Claimant in the enforcement proceedings arising out of the Award in Micula & Others v Romania [2017] EWHC 31 (Comm) (led by Sir Alan Dashwood KC and Patrick Green KC).
  • SCC Arbitration – PL Holdings v Poland (Luxembourg-Poland BIT); Matthieu acted for PL Holdings, a Luxembourg company, which prevailed in its SCC arbitration against the Republic of Poland. The claim concerned the uncompensated expropriation of our client’s equity investment in a Polish bank, in violation of the Luxembourg-Poland BIT. In its recent Final Award, the tribunal ordered Poland to pay c. €176 million in damages and €3.5 million in costs.
  • ICC Arbitration (2016) (Telecoms): Acting as junior counsel for a national telecommunications operator in a substantial ICC arbitration (foreign law).
  • LCIA Arbitration (2016) – Sale of Fuel Alcohol Contract; Acting as sole counsel in an LCIA arbitration arising out of the sale of fuel alcohol (details not public).
  • LCIA Arbitration (2016) – Transport of Ethyl Contract; Acting as sole counsel in an LCIA arbitration arising out of the transport of ethyl alcohol (details not public).
  • SCC Arbitration – Investor v State (ECT); Acting for the Claimant in arbitration commenced under the ECT and governed by the SCC rules in the energy sector in relation to breaches by an Eastern European State of the ECT (details not public).
  • ICSID Case No. ARB/14/9 – City-State N.V. et al. v Ukraine; Acting for the claimants in City-State V. et al. v Ukraine, ICSID Case No. ARB/14/9, a dispute under a bilateral investment treaty in relation to various breaches of the treaty.
  • ICC Case (2016)– Telecommunications Sector in Ukraine; Acting as sole counsel in a two-week hearing for a Ukrainian company in a commercial arbitration pursuant to the ICC Rules in relation to a dispute under a contract in the telecommunications sector (details not public).
  • Arbitration Challenge – Confidential; Advising a party in potential challenge proceedings following a bilateral investment treaty arbitration award (details not public).
  • ICSID Case No. ARB/12/1 – Tethyan Copper Company Pty Limited v Islamic Republic of Pakistan; Acting for the Respondent in Tethyan Copper Company Pty Limited v Islamic Republic of Pakistan, ICSID Case No. ARB/12/1, a dispute under a bilateral investment treaty, in relation to the refusal of a mining licence over very large-scale copper and gold deposits at Reko Diq, in Pakistan (led by Cherie Blair KC and Graham Dunning KC).
  • Arbitration Challenge – Confidential; Advising a multinational company on enforcement proceedings in various jurisdictions following a successful £8 million ad hoc award (confidential).


2017: Appointed to the Attorney General’s C PIL Panel

2015-present: Adjunct Professor of International Commercial Arbitration, Pepperdine University, London

2013: Call in England & Wales      

2011-2012: Associate, International Arbitration and Public International Law, Cleary Gottlieb Steen & Hamilton (Paris)

2011: Call in New York


2010: LLM, Georgetown University, D.C.

2010: Masters in Intentional Political Economics, Sciences Po, Paris

2008: BA in Law, Jesus College, University of Cambridge


2011: Lord Denning Scholarship, Lincoln’s Inn; Hardwicke Award, Lincoln’s Inn.

2010: Dean’s List Graduate, Georgetown University, D.C.




Spanish (Business only)