Xavier Nyssen

Xavier Nyssen

Xavier Nyssen


Paris | 32 rue de Monceau, Paris 75008
+33 1 57 57 80 01 | +33 1 57 57 80 81

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Xavier Nyssen is the former head of Dechert’s international dispute resolution practice. Since 1988, he has concentrated his practice in international arbitration, specifically in the telecom, energy, pharmaceutical and arms procurement sectors.

He has acted as counsel in numerous arbitrations whether ad hoc or under the rules of the International Chamber of Commerce (ICC), the London Court for International Arbitration (LCIA) or the European Development Fund (FED). He is also well versed in proceedings on the enforcement of arbitral awards, notably when sovereigns are involved.

Mr. Nyssen regularly advises foreign companies on collecting evidence and on the annulment of arbitration awards in French proceedings. He also acts as arbitrator.

Mr. Nyssen has been consistently recognized by both Chambers Europe and Chambers Global for his "strong track record on arbitrations in the energy, pharmaceuticals and telecommunications sectors." According to The Legal 500 Parishis human qualities enable him to comprehend not only the legal challenges of a case, but all its other aspects as well”. He is listed in The Legal 500 EMEA: France and Décideurs Stratégie Finance Droit. Sources described him as a client-oriented, technically gifted and creative practitioner who provides "very high-level advice on complex matters." In 2017 and 2018, he was listed as a leading lawyer by Who's Who Legal: Arbitration.

Before joining Dechert in 2005, he worked in New York and Brussels and served as co-managing partner of the Paris office of another international law firm, where he was responsible for the Litigation department.


Significant Representations

  • A leading European telecom company in a shareholders’ dispute exceeding US$1.5 billion. 
  • An Asian state entity in connection with a US$2 billion dispute arising from a military procurement contract and the payment of illicit commissions. 
  • A leading company in an ICC arbitration against an Asian state. 
  • A leading satellite operator in a dispute arising from a coordination agreement. 
  • A private equity house in a post-acquisition dispute under the rules of the German Institute of Arbitration. 
  • A major U.S. oil company in a dispute against a West African state involving a production sharing agreement. 
  • An Italian construction group in an ICC arbitration against a Spanish contractor. 
  • A major energy company in a shareholders’ dispute. 
  • University of Liège, M.A., 1986
  • Columbia Law School, LL.M., 1999
  • Paris, 1993
  • Brussels, 1992
  • New York, 2002
  • French
  • English

Advisory Board, Institute for Transnational Arbitration
Belgian Center for Mediation and Arbitration (CEPANI)