Quentin Declève focuses on international litigation and arbitration, as well as on EU and national competition law and international trade law. He also represents clients before European Union courts and before Belgian civil and commercial courts.

Quentin has been involved in key cases relating to restrictive measures and sanctions taken against individuals and against sovereign States by the European Union and the United Nations (Cases T-375/14 to T-378/14 on measures adopted by the European Union with regard to Egyptian citizens). More recently, Quentin coordinated the defence of the Belgian State in a dispute involving the sanctions adopted by the UN Security Council and the European Union against Libya.
In the field of competition law, Quentin assists clients both in administrative and court proceedings. In particular, he is currently intervening in the procedure to annul the Decision of the European Commission concerning State aid implemented by Belgium in favour of the Duferco group (Cases C-738/18P and C-148/19P).
Quentin is currently advising the Republic of Benin in discussions within Working Group III of the United Nations Commission on International Trade Law to reform investor-state dispute settlement mechanisms.

From 2013 to 2015, Quentin worked part-time as a teaching assistant in EU Law for Professors François Van der Mensbrugghe and Nicolas de Sadeleer at Université Saint-Louis in Brussels.


French, English, Dutch


  • Columbia Law School, LL.M., 2016
  • Brussels School of Competition, LL.M., 2014
  • University of Ghent, Exchange programme, 2011
  • University of Louvain, Master of  Laws, 2011
  • Saint-Louis University (USL), Brussels, Bachelor of Law, 2009


Quentin is the author and editor of the International Litigation Blog (www.international-litigation-blog.com) which offers posts and discussions on developments and hot topics in the field of international litigation and arbitration.

“Fortis’s Settlement: A Comparative Case Study of Securities Class Action Mechanisms in Europe and the United States” (Business Law International, 2017).

“Achmea: Consequences on Applicable Law and ISDS Clauses in Extra-EU BITs and Future EU Trade and Investment Agreements” (European Papers, Vol. 4, 2019, No. 1).

Bar admission


Notable assignments

  • Advising and representing the Republic of Benin during the UNCITRAL's discussions on the reform of investor-State dispute settlement

Publications and insights

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    • 04/02/2020
    • News

    Quentin Declève participates in 5th EFILA Annual Conference in London

    On 30 January 2020, Van Bael & Bellis associate Quentin Declève participated as a speaker in a session on the future of the Energy Charter Treaty (ECT) and intra-EU investment disputes at the 5th Annual Conference of EFILA (the European Federation of Investment Law and Arbitration) in London. The focus of Quentin’s presentation was the possibility, under the Vienna Convention of the Law of Treaties, that the European Union and its Member States might conclude an inter se agreement (i.e., an agreement between themselves) in order to remove intra-EU investment arbitration proceedings from the scope of the ECT.

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    • 07/05/2019
    • Articles

    CJEU rules that CETA ISDS mechanism is compatible with EU law

    On 30 April 2019, the Court of Justice of the European Union (CJEU) decided in Opinion 1/17 that the chapter on investor-State dispute settlement (ISDS) in the Comprehensive Economic and Trade Agreement between Canada, of one part, and the European Union and its Member States, of the other part (CETA) is compatible with EU primary law. On 29 January 2019, Advocate General Bot had already reached the same conclusion (for an analysis, see here). Opinion 1/17 removes a significant obstacle to the ratification of CETA by the EU Member States and the ratification of investment protection agreements with, for example, Singapore and Vietnam, which contain similar chapters on ISDS. The Opinion also significantly boosts the European Union negotiating position in the ongoing United Nations Commission on International Trade Law (UNCITRAL) negotiations on ISDS reform. At the same time, the Opinion might, to some extent, tie the hands of the European Union in negotiating in that forum.

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