Guillaume de Rancourt’s practice focuses on domestic and international litigation and arbitration.

He also has extensive experience in global investigations and compliance issues, with a particular emphasis on anti-money laundering, anti-terror financing, and anti-corruption matters.

Guillaume joined the firm’s Paris office in 2005. From 2008 to 2009 and from 2011 to 2012, he was resident in the New York office.

Notable Experience

  • A French Bank in federal litigation before the New York Federal Court regarding a claim brought by private plaintiffs, based upon allegations under the U.S. Anti-Terrorism Act.

  • A telecom company in annulment proceedings against an ICC award entirely defeating a $15 billion claim brought against our client.

  • A French Bank in an ICC arbitration seated in Paris and governed by French law against its former JV partner in connection with share transfer prices.

  • A global smart card company in an investigation by the World Bank’s Integrity Vice-Presidency into allegations of corruption in relation to a Bangladeshi contract, together with related internal investigations.

  • A pharmaceutical company in ad hoc arbitration proceedings, governed by French law, concerning a claim brought by a chemical company, and related annulment proceedings of the award before French courts.

  • The French State in the criminal investigation and civil proceedings for fraud arising out of the Bernard Tapie arbitral award.

  • A French copper and optical fiber products manufacturer in an ICC arbitration brought by a Chilean cable manufacturer, regarding a post-closing purchase price adjustment dispute.

  • A U.S. coal company in designing their anticorruption compliance policies and procedures.

  • A Russian oil company in successfully defending a favorable award rendered in an arbitration seated in Paris, arising out of our client’s removal from a Ukrainian oil joint venture, including the forcible takeover of the largest refinery in Ukraine.

  • A Russian oil company in successfully challenging enforcement in France of a default award obtained by another Russian oil company in 2007 in New York.

  • The Russian Federation in three UNCITRAL arbitrations initiated by one Isle of Man and two Cypriot companies in their capacities as former shareholders of Yukos Oil Company, alleging unfair treatment and expropriation in violation of the investment provisions of the Energy Charter Treaty.

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Selected Activities

  • Member, ICC, Arbitration and Alternative Dispute Resolution Commission

  • Member, ICC, Corporate Responsibility and Anticorruption Commission

  • Member, IBA, Anti-Corruption Committee

  • Teaches a course on international litigation, arbitration and investigations in a joint master’s program between Columbia Law School, Sciences Po, La Sorbonne and City University of Hong Kong (since 2017)

  • Lecturer at the Paris Bar School in “Practice of International Arbitration,” (2014 – 2016)


In Annulment Proceedings Over ICC Award, Paris Court Rules on Nature of U.S., EU, and UN Sanctions, July 10, 2020 (with Jean-Yves Garaud, Laurie Achtouk-Spivak, Camille Martini, and Christopher Moore)

Navigating COVID-19: Best Practices for Managing Compliance Risk, March 26, 2020 (with Jennifer Kennedy Park, Lisa Vicens, Amélie Champsaur, and Caroline Hailey)

Airbus Enters into a Coordinated Resolution of Foreign Bribery Investigation with U.S., U.K. and French Authorities for a Total of €3.6 Billion, February 19, 2020

Criminal Settlement Procedures in French Law: an Initial Assessment, Echanges Internationaux, February 2020 (with Caroline Hailey)

Helms-Burton Act: Possible Counterattack for European Companies, La Lettre des Juristes d’Affaires, October 14, 2019 (with Aren Goldsmith)

Trading in International Arbitral Awards: Developments in French Case Law Could Have a Chilling Effect, New York Law Journal, July 12, 2019 (with Aren Goldsmith)

End of Suspension of Title III of the Helms-Burton Act, April 19, 2019

Crédit Lyonnais and NatWest Win Summary Judgment in Long-Running Anti-Terrorism Act Litigation, April 5, 2019

French Criminal Court Orders UBS to Pay a Record EUR 4.5 Billion in Tax Fraud Case, February 28, 2019

Société Générale Enters Into First Coordinated Resolution of Foreign Bribery Case by U.S. and French Authorities, June 6, 2018

Pour une simplification du régime de la responsabilité civile de l’arbitre: plaidoyer en faveur de la notion de “faute lourde professionnelle,” Revue de l’Arbitrage, No 3, July-September 2017 (with Jean-Yves Garaud)

France Implements Sweeping Anti-Corruption Reform, March 22, 2017

France Introduces Sweeping Anti-Corruption Reform, April 19, 2016


January 9, 2020
Taught a Master Arbitrage et Commerce International (MACI) course at the firm’s Paris office

Spring 2017
Coach for University of Versailles team for Serge Lazareff International arbitration competition (CIAM)

April 15, 2016
Lecture at the EFB, “Arbitrage, droit international des contrats, clauses attributives de juridiction”

April 8, 2016
Harvard Law Arbitration Discussion Series and Career Event, “The Role, Duties and Powers of Arbitrators: Independence, Neutrality & Corruption”, Harvard Law School