Image of Guillaume Croisant

Guillaume Croisant

Dispute Resolution Managing Associate, Brussels

"I assist clients with their business-critical disputes, specialising in international and complex arbitration, litigation and investigation."


Professional experience

Education & qualifications


Guillaume is an all-round litigator specialising in international arbitration, cross-border litigation and multijurisdictional criminal and regulatory investigations. He has been appointed as an arbitrator and as a tribunal secretary under the ICC, LCIA, CEPANI and NAI rules and he is an active member of various arbitration associations. He undertook a one year secondment in the international arbitration practice of our London office in 2017-2018.

Guillaume has also extensive experience in white-collar crime, investment protection, competition litigation and business & human rights matters.

Work highlights

Guillaume has worked on a wide range of business-critical disputes. Those that can be disclosed include representing and advising:

  • Bank of New York Mellon (BNYM), in Belgian and English court proceedings, after BNYM froze the assets of the National Fund of Kazakhstan, worth some US$22bn, as a result of a third party garnishment order obtained by investors attempting to enforce an arbitral award against Kazakhstan
  • ENGIE before the Belgian Constitutional Court and civil courts in proceedings arising from the yearly taxes of c. €500m levied by the Belgian State on the nuclear energy sector
  • an Asian holding company in a €100m ICC arbitration
  • an African State in the Belgian annulment proceedings of an UNCITRAL €1bn arbitral award
  • a Belgian multinational in bribery and AML parallel investigations across five jurisdictions
  • a Belgian financial institution as respondent in parallel ICC arbitration proceedings and Belgian injunction proceedings on the disconnection of undertakings from its network in alleged breach of competition law and EU sanctions law
  • a global financial institution in a US$250m CEPANI arbitration and parallel Belgian court proceedings
  • a global bank before the EU institutions, an LCIA arbitral tribunal, and local courts in its capacity as creditor (for an amount of c. US$1bn) of an Eastern European group in financial distress benefitting from protectionist measures adopted by its home State

Professional experience

Guillaume lectures on written and oral advocacy and private international law at the Université libre de Bruxelles (ULB). He monitors the legal developments in this field for the Journal des Tribunaux and the Revue de Droit Commercial Belge and he is the author of numerous contributions in treaties and legal journals on various topics relating to his professional practice, such as international commercial and investment arbitration, private international law, business and human rights, third party funding and class action.

Guillaume has worked on a number of pro bono and community investment initiatives of the firm, including by delivering trainings on business and human rights in Kenya (with Advocates for International Development), contributing to the 2nd edition of the Guide for General Counsel on Corporate Sustainability (with the United Nations Global Compact), and drawing up a European database of asylum law (with the European Council on Refugees and Exiles; finalist of the 2016 European Award for Exemplary Partnership in the Public Interest).

Education & qualifications

Guillaume was admitted to the Brussels bar in 2014 (Prix George Boels).

He holds a Magister Juris from the University of Oxford (Brasenose College, Wiener Anspach Foundation Scholar) and a Bachelier en droit and a Master en droit from the Université libre de Bruxelles (Prix René Marcq, Prix André Bruyneel, Premier Prix d’Excellence).

Guillaume speaks French, English and Dutch.