Flexstone Partners To Acquire Glouston Capital Partners To Form $15 Billion Private Equity Platform

By Amit Chowdhry • Jun 18, 2026

Flexstone Partners announced it has agreed to acquire Glouston Capital Partners, a Boston-based private equity secondaries manager with over $3.4 billion in assets under management. The financial terms of the transaction were not disclosed.

Flexstone is a global private markets investment manager with $12 billion in assets under management and an affiliate of Natixis Investment Managers, which has $1.4 trillion in assets under management.

The combined platform will manage more than $15 billion in assets across primary, co-investment, and secondary strategies. It will serve institutional investors across North America, Europe, and Asia.

The combination brings together Flexstone’s global primary and co-investment platform with Glouston’s North American secondary capabilities. Flexstone said the businesses operate primarily in distinct geographies with minimal strategic overlap.

Glouston’s team, General Partner relationships, and focus on the North American middle market are expected to strengthen Flexstone’s secondaries platform and expand the private equity strategies it can offer institutional investors.

Flexstone’s investment and management teams will remain intact. Glouston’s investment strategy and investment team will also remain intact after the transaction closes. The six Glouston partners will continue managing the secondary business from Boston using the same investment process and criteria that have defined the firm’s strategy.

As part of the transaction, Glouston’s partners will roll a substantial portion of their equity into the combined firm and become Managing Partners of Flexstone. Flexstone partners will also invest additional equity alongside Glouston’s team.

The combined platform will operate across five offices in New York, Boston, Paris, Geneva, and Singapore, with 37 investment professionals. Flexstone will continue managing primary and co-investment strategies across private equity, private debt, infrastructure, and real estate.

Glouston will lead the combined firm’s secondary strategy and U.S. distribution. Flexstone’s secondary team, consisting of three professionals in Europe and one in New York, will join forces with Glouston’s investment leadership.

Glouston’s strategies will be rebranded under the Flexstone Partners name following the close of the transaction. The Glouston team will continue operating from Boston as part of Flexstone’s expanded global platform. Existing fund structures, LP agreements, and investment mandates will not be affected by the rebranding.

KEY QUOTES:

“Flexstone Partners is pleased to welcome Glouston Capital Partners’ experienced team as we move into a new phase of growth. Glouston’s team brings a complementary investment philosophy to the middle-market landscape and a long history of disciplined execution. Their secondaries expertise aligns with our culture and expands the breadth of strategies that Flexstone can offer investors across our private equity platform.”

Eric Deram, Managing Partner and CEO of Flexstone Partners

“This partnership is a natural evolution for Glouston Capital Partners. Flexstone’s global platform, complementary GP relationships, and strong distribution network will allow us to expand our reach while preserving the investment discipline and team-based decision-making that our LPs value. We are excited to join forces and continue building a leading secondary platform with the resources and scale to compete effectively in today’s market.”

Red Barrett, Senior Managing Partner of Glouston Capital Partners

“We are seeing rapidly growing demand from investors for scaled, high quality private markets solutions. Private assets are a core pillar of Natixis Investment Managers’ long term growth plan with Flexstone Partners playing an essential role. Glouston Capital Partners’ seasoned team, deep institutional relationships, and differentiated middle market focused strategy nicely complement Flexstone’s private equity business. This newly integrated entity is uniquely positioned to meet the evolving needs of clients in one of the fastest growing segments of private markets.”

Philippe Setbon, CEO of Natixis Investment Managers