Team
Our team has considerable and relevant investment know-how and deep understanding of the challenges and opportunities across our investment themes.
Our team members gained professional experience in top tier institutions such as Bain & Company, Morgan Stanley, Natixis, AXA Investment Management, Linklaters or Edmond de Rothschild.
Our team builds on a diverse educational and cultural background from across Continental Europe, the UK, the Middle East and North America. We believe in inclusivity.

Jean Baptiste Oldenhove
Founder & Investment Partner
Jean Baptiste founded Estari after a decade at TREIS Group, a sustainability direct investments platform. Under Jean Baptiste’s leadership, TREIS Group became a recognised European pioneer in sustainability with investments in clean energy, agricultural biotechnologies, alternative proteins and circular economy in fashion and textile. Prior to TREIS, Jean Baptiste worked for 3 years at Bain & Company. He started his career as an R&D Engineer at STMicroelectronics.
Jean Baptiste holds a MSc in Engineering from Ecole Polytechnique de Louvain and an MBA from the Wharton school.

Brieuc De Witte
Business Development Partner
Before joining Estari in 2022, Brieuc was heading French Wholesale Distribution at Natixis Investment Management for 8 years. Prior to that, he held various positions in Sales and Client Relationship Management at AXA Investment Managers. Brieuc holds an MS in Management Controlling from ESCP Business School and a BA in Business from ESSCA Ecole de Management. Brieuc’s commitment to Sustainability includes both his professional and personal life from working on the design & launch of several sustainable investment funds since 2006, as well as assisting NPOs or high impact businesses in the development of their activities.


Sebastien Mahieu
Strategic Partner
Before joining Estari, Sébastien was a Senior Private Banker at Edmond de Rothschild, focusing on HNWI and entrepreneurs, and taking the leadership on the development of Private Equity and Socially Responsible Investments for the Belgian branch. Prior to that, he held various positions in Private and Corporate Banking at BIL, ING and Fortis Bank. Sébastien holds Master in Management from the Louvain School of Management, Université Catholique de Louvain, and Executive Master in Management from Solvay Brussels School, Université Libre de Bruxelles

Gaetane Schaeken
Legal Counsel
Gaetane has more than 10 years of experience with the Magic Circle law firms (Linklaters and Freshfields) as a corporate and capital markets associate. She is also a university lecturer at the University College of London in the UK and the Université catholique de Louvain in Belgium. Gaetane holds a Law Degree and PhD in financial markets law from the Catholic University of Louvain and Columbia University.
Advisors
The team is supported by an extensive network of advisers from the private, corporate, academic and public policy spheres who offer guidance on investment considerations.
This network is at the core of the support to portfolio companies on various issues, such as strategy, finance, governance, recruitment, development and impact measurement.