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HEC - Ecole des Hautes Etudes Commerciales, H.E.C. diplôme

Georgetown University Law Center, LL.M.

Université de Sceaux, Paris-Sud XI , Maîtrise de droit des affaires




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Geoffroy Lyonnet
PHONE: +33 1 42 66 39 10
FAX: +33 1 42 66 39 62

Mr. Lyonnet, managing partner of the Paris office, is a partner in the International Arbitration and Corporate groups. His practice focuses on international arbitration and dispute resolution. He also has experience in domestic and international business law matters and transactions.

Mr. Lyonnet is ranked as a leader in international arbitration by Chambers Global 2013-2018, with clients highlighting his "outstanding profundity in the analytical work done", as well as being “really outstanding, effective and impressive,” and "personable, likeable and comes across as someone who talks good sense". He is also recognised by Legal 500 EMEA 2012-2016, in which he is described as "truly international in background, experienced and brilliant in evidentiary exposition" and "on top of all the relevant details".

His arbitration activities have involved international disputes in a variety of fields, including mergers and acquisitions, oil & gas, concessions, agriculture projects, distribution and construction under diverse applicable laws and arbitration rules, including International Chamber of Commerce (ICC), International Centre for Settlement of Investment Disputes (ICSID), United Nations Commission on International Trade Law (UNCITRAL) and SCC rules. His experience includes the representation of private-sector companies and sovereign States or State-owned entities in international arbitrations. Mr. Lyonnet has also served as arbitrator, sole arbitrator and party-appointed arbitrator, and as an expert witness in French and international arbitration law before U.S. courts.  He also lectures on international arbitration.

Mr. Lyonnet’s corporate experience also includes mergers; acquisitions; investment management and funds, and international contracts, including distribution agreements and contracts relating to the exploration, production sharing, shipment and commercialization of natural gas and satellite network communication contracts with both private and State-owned entities.

Prior to joining the firm in 1988, Mr. Lyonnet worked with Unilever.


Paris Bar, Commission on International Arbitration

International Bar Association

International Chamber of Commerce (ICC) Member and listed arbitrator, Commission on International Arbitration Member, Commission on Arbitration

Co-Chair, Task Force on National Rules of Procedure for Recognition and Enforcement of Foreign Arbitral Awards Pursuant to the New York Convention of 1958

Comité Français de l’Arbitrage (French Committee on Arbitration)

Association des Juristes en Arbitrage (Association of Arbitration Practitioners)

Institut pour l’Arbitrage International (International Arbitration Institute)

Union Internationale des Avocats (International Association of Lawyers)


Chambers Global 2013-2018 – France: Recommended for International Arbitration

Legal 500 EMEA 2012-2016  - France: Recommended for Dispute Resolution: International Arbitration

Who’s Who Legal – France 2017: Recommended for Arbitration

International Lawyers