Bart Legum

Honlet Legum Arbitration

68 rue du Faubourg Saint-Honoré
75008, Paris, France

Tel: +33 6 87 73 89 56

Tel: +33 1 79 35 22 21


Peers and clients say:

"Bart is a class act, he is top of his field and prepared for any situation"
"He is a top practitioner"
"He is absolutely excellent at what he does"


Barton Legum is a partner at Honlet Legum Arbitration. He has over 30 years’ experience serving as counsel or arbitrator in complex international disputes. He is a member of the board of the Arbitration Institute of the Stockholm Chamber of Commerce and the ICSID Panel of Conciliators (appointed by ICSID) and serves as editor of The Investment Treaty Arbitration Review and International Litigation Strategies and Practice.

Describe your career to date.

After studying public international law for a year at the Paris II law faculty, I returned to my native US to clerk for a federal appeals court judge. I then practised at Debevoise & Plimpton in New York for 13 years litigating a wide variety of civil and commercial cases, most containing a cross-border element. My career in arbitration began in earnest at the end of the last century. The US State Department recruited me to lead the US defence of the first arbitrations against it under the NAFTA’s investment chapter. I led the State Department NAFTA team from 2000–2004, winning every case heard during my tenure.

Love led me to move to Paris. I have practised international commercial arbitration and investment treaty arbitration here for the past 19 years. My practice has primarily been as counsel, but I increasingly sit as an arbitrator and as a mediator.

How do you prepare for complex cross-border arbitration proceedings?

Reading, reading and more reading. My goal is, when sitting as an arbitrator, to understand the issues sufficiently before the hearing to identify the key questions I would like answered. Ideally these questions are posed to the parties sufficiently in advance for counsel to take them into account at the hearing. But this is possible only if the other arbitrators can also prepare themselves to this level well before the hearing.

What do you believe are the most important issues for clients when looking to begin an arbitration?

The key is to understand that there is only one chance to win. The absence of an appeal means that in arbitration there is no second chance. Arbitration requires an intensity of effort and focus in preparing the case that may be different from that in court litigation.

How has the role of arbitrator changed since you started your career?

The role has not changed as much as the users’ expectations. Users today expect a higher degree of professionalism, technical expertise, devotion and responsiveness.

What are the challenges of managing an abundance of data and information? How can these challenges be overcome?

My practice has been paperless for about a decade. Taking this step provided me with a significant productivity boost. Being able easily to access any relevant document concerning the case from anywhere at any time makes a huge difference. This makes working remotely or while travelling much more efficient.

What trends do you see currently emerging in international arbitration?

A significant uptick in arbitration work in all sectors.

Looking back over your career, what is the most interesting arbitration you have been a part of?

I actually find all of my cases to be interesting. It is hard to single out one in particular, but what comes to mind is the Methanex v United States case. It came at a time when there was little jurisprudence to guide the debate, presented a perfect storm of policy issues and the hearing featured a fascinating “play within the play”: there was an evidentiary hearing on whether certain evidence had been illegally obtained that took place during the merits hearing, with a different cast of characters and a different set of issues to be decided.