40 under 40

“amongst the most promising rising stars in international arbitration”

Who's Who Legal

“a rising star of the Swiss arbitration community”

Who's Who Legal

“strong academic”

Who's Who Legal

“great advocacy skills”

Who's Who Legal

“very proactive, sharp and trustworthy”

Who's Who Legal

“unanimously applauded for his excellent work on complex proceedings”

Sebastiano Nessi

Sebastiano Nessi is a Counsel in our International Arbitration Group in Geneva. Trained in both civil and common law, Sebastiano has advised and represented clients in numerous commercial and Investor-State arbitrations, both ad hoc and under each of the major institutional rules. Sebastiano also sits as an arbitrator.

Leading directories have described Sebastiano as one of "the most promising rising stars in international arbitration" (40 under 40), and a "rising star of the Swiss arbitration community" (Who's Who Legal). He is praised by peers and clients for being "a very proactive, sharp and trustworthy lawyer" and "a strong academic with great advocacy skills" (Who's Who Legal). In 2020, Sebastiano was ranked as 3rd Most Highly Regarded Individual in Europe by Who's Who Legal Future Leaders Arbitration.


  •  Has acted as counsel for Swiss and international clients (including states and state-owned entities) in a range of complex (commercial and investment) arbitrations, both ad hoc and under each of the major institutional rules, with seats in Geneva, London, New York, Paris, Singapore, Stockholm and Vienna
  • Has  represented clients on a range of court applications before Swiss courts including the Swiss Supreme Court
  • Has advised clients on the structuring of their investment and states on the negotiation and drafting of trade and investment treaties
  • Has a broad range of expertise with a particular focus on energy, oil & gas, commodities, pharmaceuticals, sales and distribution, banking, aerospace, construction and sports disputes
  • Sits himself as an arbitrator 


Professional Experience
Counsel at Schellenberg Wittmer
Senior Associate at Schellenberg Wittmer
Senior Associate at Allen & Overy LLP, Paris
Associate in a major Swiss law firm in Geneva
Education and Admission
Certificate of Advanced Studies in arbitration, University of Lucerne and University of Neuchâtel
Arbitration Practitioner (ArbP) Diploma, Swiss Arbitration Academy
LL.M., Columbia Law School, New York
Bar Admission in Switzerland
Master of Law, University of Geneva
Additional Professional Activities
  • International Chamber of Commerce (ICC YAF) Representative for Europe and Russia
  • Executive Member of the Global Steering Committee of the Chartered Institute of Arbitrators (CIArb YMG)
  • Lecturer on commercial and investment arbitration at the University of Paris I, Panthéon-Sorbonne, Sciences Po Law School, the Swiss Arbitration Academy, and the Ukrainian Arbitration Association's Arbitration School

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