Alantra advises Albarest Partners and Definvest (Bpifrance) on the sale of MASA to Nicolas Walewski

Mar 2026

Sell-side advisory

Paris – Alantra acted as M&A sell-side advisor to Albarest Partners, MASA’s majority shareholder, and Definvest, the defense investment fund managed by Bpifrance, on the sale of their stakes in MASA to Nicolas Walewski, a private investor with recognized expertise in the defense sector.

Founded in 1996, MASA is one of the global leaders in constructive simulation and decision-support software for the defense and civil security markets. Its patented AI-powered solutions support command training, crisis management, complex exercise preparation and after-action analysis for armed forces, government bodies and other institutional users.

Alantra conducted a process that generated strong interest primarily from French, European, North American, and Middle Eastern strategic buyers. 

Oriane Durvye, Managing Partner at Alantra, said: “MASA has built a distinctive position in a highly strategic segment of the defense software market, combining advanced simulation capabilities, patented AI technology and a strong international footprint. We are proud to have advised the selling shareholders on this transaction and to have supported them in joining the right partner for the Company’s next phase of development.”

This transaction represents another high-quality defense technology credential for Alantra and adds to its strong track record in the two sectors, with 17 deals completed in technology and 7 in aerospace & defense in the last 12 months. Recent deals include advising JPB Système on the sale of a minority stake to Ardian, GRAX on its sale to Ascendx and Orange Business on the sale of Océan, its fleet management business, to Shiftmove.