Marion Chabrost

Marion Chabrost is a Senior Associate in the Paris office at RBB Economics.

Her experience includes merger assessments, abuse of dominant position, horizontal agreements, as well as follow-on damages.

Before joining RBB in 2026 she served as Senior Economist at another leading economic consultancy. She holds a PhD from the Paris School of Economics.

Marion has advised on numerous high-profile merger cases, including transactions in mobile telecommunications (Orange / Voo), sports retail (JD Sports / Groupe Courir), pharmaceuticals (GSK / Pfizer), nuclear services (Westinghouse / Cameco), media (TF1/M6), transport services (Keolis / CarPostal), and heavy industry (Lafarge / Holcim). Her experience covers both Phase I and Phase II investigations, including cases subject to commitments.

She has also worked on cartel and abuse of dominance matters, providing economic assessments of competitive effects and damages in regulatory investigations and follow-on litigation, including cases in the automotive, food manufacturing, aviation and consumer goods sectors.

She has advised clients before the European Commission, the CMA and national competition authorities on complex cases across a wide range of sectors.

A French national, Marion is fluent in English and French.