Flexstone Partners, a Natixis‑affiliated private‑markets manager, agreed to buy Boston‑based secondaries specialist Glouston Capital Partners. The deal creates a $15 billion platform that blends Flexstone’s $12 billion primary and co‑investment business with Glouston’s $3.4 billion middle‑market secondary portfolio. The transaction signals a push for scale in the private‑equity space.

Both firms keep their investment teams intact, with Glouston’s six partners moving into Flexstone as Managing Partners while rolling significant equity into the new entity. Flexstone’s four‑strong secondary group will join Glouston’s operations in Boston, and the combined arm will operate from New York, Paris, Geneva, Singapore and Boston, spanning five offices for investors worldwide.

Glouston’s track record of more than $2.9 billion invested across 290 secondary transactions anchors the new secondary strategy, which will rebrand under the Flexstone name after completion. Existing fund structures, LP agreements and mandates remain unchanged, while the partnership preserves Glouston’s disciplined, team‑based decision making that its limited partners value. The deal aligns incentives tightly today.

Natixis Investment Managers, which oversees roughly $1.4 trillion and sits within France’s Groupe BPCE, welcomed the deal as part of its strategy to meet growing investor demand for high‑quality private‑market solutions. With 37 investment professionals, the combined platform will offer a broader array of strategies, from primary co‑investments to middle‑market secondaries, strengthening its competitive position globally.