Pierre-Olivier Mahieu

Pierre-Olivier Mahieu


Pierre-Olivier specialises in mergers and acquisitions, private equity, corporate litigation and equity capital market transactions.

He advises both local and international clients on inbound and outbound transactions, with more than 25 years of experience on Belgian, European and other cross-border transactions.

Pierre-Olivier’s standing in the profession earns him regular praise from the top legal directories: “He has the charisma to excel in difficult situations with highly demanding counterparts” (Chambers & Partners, 2023); “Pierre-Olivier Mahieu [is a] prolific senior dealmaker” (Legal 500, 2023).

He is fluent in French, Dutch, English and Spanish and has a basic knowledge of Mandarin.


Representative matters

European Payments Initiative (EPI), an initiative of 16 European banks and payments institution, on their acquisition of the leading Dutch payment scheme Currence iDeal and the Luxembourg-based payment solution provider Payconiq International, from their current shareholders.

Athora Belgium, the Belgian life insurer focused on pension and investment savings, on the acquisition of a life insurance portfolio, with EUR 3.3 billion of assets under management, from NN Insurance.

Alcopa Coordination Center on the sale of their subsidiary Bihr, a group specializing on the distribution of motorcycle parts, to US-based Arrowhead Engineered Products.

I-care, a Walloon specialist in predictive maintenance, on a capital increase of EUR40m from existing and new shareholders. 



Candidat, Law, Facultés Universitaires Saint-Louis, 1986
Law Degree, Université Catholique de Louvain, 1989
LLM, Law, University of Virginia, 1991


French, English, Dutch, Spanish
A&O Shearman was formed on May 1, 2024 by the combination of Shearman & Sterling LLP and Allen & Overy LLP and their respective affiliates (the legacy firms). Any matters referred to above may include matters undertaken by one or more of the legacy firms rather than A&O Shearman.