Marc Ynzonides

Marc worked in the litigation and arbitration practice of De Brauw Blackstone Westbroek for over 20 years, five of which he also served as member of the board of this firm. Marc has represented clients on a broad spectrum of issues up to the Supreme Court level. Prior to moving to private practice, Marc worked as an assistant professor in civil procedural law and insolvency law at the Erasmus University. He holds a PhD on the topic of default judgments and setting aside (Verstek en verzet, Kluwer 1996). Marc published extensively on civil procedural law, and in relation to his, has held a number of additional positions: Marc was member of the Advisory Committee for Civil Procedural Law of the Ministry of Justice, substitute member of the Amsterdam Disciplinary Board for Attorneys and president of the Association of Supreme Court Attorneys. Marc currently acts as deputy judge at the District Court Midden-Nederland and he is member of the Supervisory Board of APM Terminals Maasvlakte II B.V. Marc also regularly acts as arbitrator.


Setting aside proceedings in respect of three UNCITRAL arbitral awards worth USD 50 billion issued against the Russian Federation under the Energy Charter Treaty

Legal proceedings against an Italian manufacturer regarding the cancellation of an order for several high-speed trains

Acting on behalf of a big four audit firm in various disciplinary and civil proceedings on professional liability

Real estate – Pensions
Assisting a pension fund in recovering losses in the amount of hundreds of millions of euros from the defendants in the Klimop case, one of the largest fraud cases ever tried in the Netherlands involving a complex and extensive fraud scheme in the real estate sector

NAI arbitration for a major Dutch insurance company regarding the interpretation and applicability of a settlement agreement


Since 2019
Ysquare | Attorney

De Brauw Blackstone Westbroek | Attorney

De Brauw Blackstone Westbroek | Board Member

Erasmus University Rotterdam | Assistant professor civil procedural and insolvency law


Since 2019
AMP Terminals Maasvlakte II B.V. | Member of the Supervisory Board 

Since 2019
District Court Midden-Nederland | Deputy Judge


Erasmus University Rotterdam | Ph.D

Erasmus University Rotterdam | LL.M.


The chronicle of Dutch civil procedural law (‘Kroniek van het burgerlijk procesrecht’), Nederlands Juristenblad (NJB), 2011-2014, 2016-2017, (co-author Margriet de Boer)

Docket regulations: from regional to national and back again (‘Rolrecht: van regionaal naar landelijk en weer terug?’), in: Middelen voor Meijer, 2013

Complexity and massification in civil procedural law (‘Complexiteit en massificatie in het burgerlijk procesrecht’), in: Opstellen ter gelegenheid van het 200 jarig bestaan van het genootschap Iustitia et Amicitia, 2010

A guide to the NAI arbitration rules: including a commentary on Dutch arbitration law, 2009 (co-editors Marnix Leijten and Bommel van der Bend)

Dutch civil procedural law (‘Nederlands burgerlijk procesrecht’), Deventer: Kluwer 1993, 1997 and 2002 (co-authors Henk Snijders and Gerard Meijer)


Dutch, English