A&O Shearman advised Sia Partners, a global, next-generation independent management and AI consulting firm, in a minority investment of up to EUR250m from funds managed by Blackstone, the world’s largest alternative asset manager, to support Sia’s continued growth.

Sia Partners founder and chief executive officer, Matthieu Courtecuisse, retains a significant majority stake in the company and will continue to lead the company. The Blackstone investment marks Sia’s first partnership with a financial investor since its founding in 1999. 

With 3,000 employees across 20 countries and 50 offices, Sia is a leading player in the global consulting market, recognized for its deep expertise in strategy, management consulting and AI, and the ability to leverage AI technology and data to drive business transformation. Sia’s clients feature Fortune 500 companies across the sectors of Energy, Banking, Consumer, Luxury and Retail and TMT. The Blackstone investment was announced on December 16, 2024, in a press release.

“Working with Sia Partners provided A&O Shearman an opportunity to showcase the broad reach of our cross-border M&A practice and close partnership with companies at the forefront of innovation in a transaction that resonates with A&O Shearman’s own early adoption of AI in the legal practice,” said M&A partner Romain Dambre “We were very pleased to assist the Sia Partners team in this pivotal investment from Blackstone.”

The A&O Shearman team was led by M&A partners Olivier Thébault (Paris) and Romain Dambre(New York) and involved a cross-border team that included M&A partner Romy Richter (Paris), M&A associates Jade Billère-Mellet, Christos Ierna, Myriam Azmy, and Bénédicte Cheyrou-Lagrèze (Paris), M&A associates Iqra Anees and Nwadi Oko (both of New York). Tax partner Charles Del Valle, tax associate Ageu Pires, and tax jurist Ryan Ceglia, debt finance partner Thomas Roy and debt finance associates Jonas Brucker and Antoine Duez (all of Paris).