Geoffroy Lyonnet impresses sources with his "attention to detail and advocacy skills." He frequently act for sovereign states facing private investors in investment arbitrations.

Geoffroy Lyonnet is best known for his work on investor-state disputes. He also acts on ICC rules commercial arbitrations and co-ordinates subsequent enforcement actions with local counsel. Interviewees say that he is "thoughtful and knowledgeable."

Known for his advocacy, Geoffroy Lyonnet serves as both lead counsel and arbitrator and was instrumental in the Kazakhstan Oil Field case.

Geoffroy Lyonnet is recognised in the market for his strong cross-examination skills. He is experienced handling investor-state arbitrations and commercial arbitrations, with notable activity in oil and gas sector disputes.

Sources say: "He has shown outstanding profundity in the analytical work done."

Geoffroy Lyonnet est également très expérimenté.

"really outstanding, effective and impressive." His practice focuses on commercial and investment arbitrations, and he is a favourite with clients: "He's personable, likeable and comes across as someone who talks good sense."

Geoffroy Lyonnet is ‘on top of all relevant details.’