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Tone Oeyen


Antitrust and competition | Artificial intelligence | Foreign direct investment and national security | International trade | Life sciences | Technology |

Tone displays superb quality and subject-matter expertise. His big strength lies in daring to make decisions in complex and sensitive matters

Chambers Global 2023

Profile details

About Tone Oeyen

Tone specialises in European and Belgian competition law, with a particular focus on cross-border merger control and cartel enforcement, and multi-jurisdictional foreign investment reviews.

He also advises on abuse of dominance and state aid, as well as on general EU and international trade law and trade defence measures.

Tone has significant experience of complex merger proceedings before the European Commission and other global authorities, which often include the negotiation of remedies.

His conduct practice covers anti-competitive behaviour in all areas, including issues raised by digital transformation, and he has successfully defended clients in cartel and state aid-related litigation before the Belgian and European courts.

Tone is a member of the firm’s foreign investment group and advises clients on Belgian foreign investment review proceedings.

He speaks Dutch, English, French, Spanish and German.

Recent work

  • UBS on the global merger control and foreign investment aspects of its acquisition of Credit Suisse.
  • Yokohama Rubber Co on obtaining unconditional phase I merger approvals from the European Commission and the UK Competition and Markets Authority (CMA) for its €2.1bn acquisition of Trelleborg Wheel Systems, a manufacturer of off-highway tyres for agricultural and industrial machinery.
  • Cargotec on its proposed merger with Konecranes in the cargo handling industry to create a combined group with sales of €7bn, involving the first parallel phase 2 review of a transaction by the CMA and the European Commission.
  • Meta on its defence against the EC and UK CMA's parallel antitrust investigations into Facebook Marketplace, and on its defence and coordination of other antitrust proceedings around the world.
  • Meta on its landmark challenge against the EC before the EU General Court, with Meta having obtained rarely granted interim relief from the Court.
  • Siemens on the worldwide merger control proceedings of the proposed transformative combination of Siemens' and Alstom's mobility businesses, which is now widely recognised as a landmark case for the European merger control regime.
  • Boehringer Ingelheim on the global merger control aspects of its $22bn asset swap with Sanofi. The deal, which transformed the parties into global leaders in animal health and consumer healthcare respectively, prompted merger filings in over 20 countries, including a rare triple 'fix-it-first' phase one clearance from the European Commission.
  • Solvay on the global competition law aspects of some of its most recent important business reshaping transactions, including its $5.5bn acquisition of Cytec and its €4.3bn 50:50 joint venture with INEOS.
  • Several clients in the context of cartel investigations by Belgium’s competition authority (the BCA) and ensuing litigation before the Belgian courts.



  • New York University School of Law, US (LLM in trade regulation,  2009-2010)
  • Ghent University, Belgium (master of law, summa cum laude, 2007-2009; bachelor of law, cum laude, 2004-2007)