Biography

Prior to joining Weil, Marie-Marie was an associate with an international law firm, and was based in both Brussels and New York. She represented companies before the U.S. antitrust agencies, as well as advised clients in cartel and abuse of dominance matters before the European Commission and national competition authorities. Marie-Marie also worked as a contractor for the United Nations Conference on Trade and Development and interned at the European Commission – DG Competition and the Austrian Competition Authority.
Marie-Marie was a Harlan Fisk Stone Scholar at Columbia Law School where she received an LL.M. degree. Prior to attending Columbia Law School, Marie-Marie graduated magna cum laude from the College of Europe in Belgium where she received an LL.M. degree in European Legal Studies. She also earned a Master in Law with a specialization in European Law from Université Catholique de Louvain and her Bachelor’s Degree from Facultés Universitaires Notre-Dame de la Paix.
Marie-Marie has an extensive pro bono practice and is admitted to the New York State Bar.
Latest Thinking, Firm News & Announcements
Latest Thinking
- Revisions to HSR Act Filing Thresholds, Fee Structure and Civil Penalties, and Revisions to Clayton Act Section 8 Thresholds Alert — Antitrust/Competition — By Vadim M. Brusser, Michael C. Naughton, Alexis Brown-Reilly, Dan S. Nobil and Marie-Marie O. de Fays — PDF — January 24, 2023
- Major Changes to HSR Filing Fees Alert — Antitrust/Competition — By Vadim M. Brusser, Michael C. Naughton, Alexis Brown-Reilly, Dan S. Nobil and Marie-Marie O. de Fays — PDF — December 29, 2022
- Blockchain Collaborations: Analyzing the Potential Antitrust Implications Publication — Competition Law Insight — By Marie-Marie O. de Fays — May 13, 2020
- Predicting Competition in Digital Markets Publication — IFLR — By Marie-Marie O. de Fays — December 05, 2019
- UNCTAD Peer Review Mechanism for Competition Law: 10 Years of Existence Publication — New York & Geneva — By Marie-Marie O. de Fays — PDF — 2015
Firm News & Announcements
- Weil Advised Blackstone in its $1B Sale of Aqua Finance, Inc. Deal Brief — July 29, 2022
- Weil Advised Vonage Holdings Corp. in its $6.2B Sale to Ericsson Deal Brief — July 21, 2022