Our people

Marnix Somsen


  • Profession
    Advocaat, admitted to the Bar in the Netherlands in 1996
  • Expertise
    Financial Markets Regulation, International trade, Regulatory Enforcement
  • Languages
    Dutch, German, English, French
  • Education
    University of Amsterdam, Harvard Law School, Columbia Law School


Marnix Somsen specialises in regulatory and criminal enforcement. He represents corporations and financial institutions subject to investigation and enforcement proceedings. His experience spans both the US, Europe, Africa and Asia. Recent work includes representing publicly listed companies in enforcement actions brought by the SEC, the FED, OFAC, BIS, the DoJ, the CFTC, the FCA, the SFO, BaFin, the AMF, the HKMA, the MAS, the JFSA, DNB, the OM and the AFM on a variety of regulatory and criminal charges.


Marnix typically handles cross-border enforcement matters and internal investigations for EU companies involving one or more US or other foreign regulators, drawing upon the resources of our international Best Friends network. Over the past few years, issues have included:

  • Libor and other financial benchmarks
  • FCPA and UKBA
  • other anti-bribery statutes
  • international sanction programs (UN, US, EU, Worldbank)
  • export controls
  • anti-money laundering
  • insider trading
  • market & price manipulation
  • banking & securities fraud
  • regulatory compliance failures


Marnix’s work includes international coordination among local law firms, reputational damage mitigation, remedial & disciplinary measures, press relations, market disclosures, dealing with whistleblowers and managing voluntary self-disclosures. Currently the co-chair of the IBA Anti-Corruption Committee for the Netherlands, Marnix has recently co-edited Onderneming en Sanctierecht, a Nijmegen University textbook on regulatory and criminal enforcement. Formerly an editor in chief of Tijdschrift voor Sanctierecht & Compliance, the Dutch enforcement & compliance law review, Marnix now serves on its Board of Advisors.

News and publications

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