Gresham House to acquire SUSI Partners

Gresham House and the shareholders of SUSI Partners AG (‘SUSI Partners’), a Switzerland-headquartered specialist investment manager focused on energy transition infrastructure, have entered into a definitive agreement under which Gresham House Holdings Limited will acquire SUSI Partners AG.

Key highlights:

• Combines Gresham House’s market leadership in UK battery energy storage¹ with SUSI Partners’ comprehensive equity and credit expertise in global energy transition infrastructure
• Provides clients with a broader range of strategies across equity, credit, co-investment and tailored solutions to deliver attractive risk-adjusted financial returns whilst advancing decarbonisation
• Extends Gresham House’s geographic reach into continental Europe and Asia, accelerating international growth ambitions
• SUSI’s CEO Marco van Daele will lead the newly combined Energy Transition division

By combining SUSI Partners’ comprehensive mid-market energy transition investment capabilities across equity and credit with Gresham House’s UK leadership in battery energy storage, the transaction positions Gresham House as a leader in key growth segments of the global infrastructure investment market. It will also expand Gresham House’s access to continental European and Southeast Asian markets, supporting its ambition to become a leading global alternative asset management firm. With £2.7 billion (EUR €3.1 billion) in AUM, the combined Energy Transition business will rank among Europe’s top 10 in energy transition asset managers by AUM².

Gresham House and SUSI Partners will combine highly complementary investment strategies, client bases, and cultures, allowing for a high degree of operational continuity. From completion of the transaction, all SUSI Partners’ employees will join Gresham House and SUSI Partners’ CEO Marco van Daele will lead the newly combined Energy Transition division. Ben Guest, a Managing Director at Gresham House Asset Management and the lead Fund Manager of Gresham House Energy Storage Fund plc (GRID), will continue to lead the UK-based Energy Transition team and drive growth in energy storage strategies. SUSI Partners’ portfolio management leads will continue to manage current and follow-on products within the division’s Equity, Credit, and Asia strategies.

The transaction remains subject to customary closing conditions including regulatory approvals. Financial terms have not been disclosed.

Tony Dalwood, CEO of Gresham House, commented:

“Global investment in energy transition reached a record $2.1 trillion last year and would need to rise to $5 trillion annually by 2035 to achieve net zero emissions by 2050³. The acquisition of SUSI Partners will strengthen our ability to meet this demand across equity and credit, combining market-leading expertise with deep local knowledge in Europe and Asia. Expanding our geographic reach will also give our growing international client base access to a wider range of strategies, co-investment opportunities and tailored solutions managed by proven teams. Together, we will be better placed to deliver financial returns by investing in the global themes shaping the future.”

Marco van Daele, CEO of SUSI Partners, said:

“Joining forces with Gresham House is an exciting new chapter for SUSI Partners and allows us to take the next step in our mission to deliver attractive investment solutions generating impactful returns for our clients. The combination brings together two complementary platforms with shared values, deep sector expertise, and a strong commitment to long-term partnerships. I look forward to leading our expanded energy transition business and to continuing to serve our investors with focus and ambition.”

As part of Gresham House, SUSI Partners’ portfolio management teams will continue to focus on energy transition investment opportunities across renewable energy production, energy efficiency, energy storage, and the electrification of transport and heating, among other themes. SUSI Partners remains fully focused on its equity strategy and plans to grow its European credit strategies, targeting a crossover infrastructure debt risk profile. A follow-on Southeast Asia strategy is also planned for 2026. Combining SUSI’s deep energy transition expertise with the wider specialist sustainable investment approach of Gresham House is expected to create further opportunities for investment management and product development in the future.

With this transaction, Gresham House continues to grow AUM and deploy capital internationally, through the delivery of accretive M&A alongside organic growth. The transaction will see Gresham House’s AUM increase to £10.2 billion (EUR €11.9 billion). In addition to energy transition infrastructure, its investment strategies span forestry, natural capital, sustainable infrastructure, real estate, and public and private equity.

1. Gresham House Energy Storage Fund plc (GRID) is the largest UK-listed investment company investing in this market, as measured by operational capacity, and is managed by Gresham House Asset Management Limited, part of Gresham House.
2. Indefi, June 2025 based on 10-year fundraising in European-focused renewables funds by European GPs (excluding industrial-affiliated players) as of year-ending 2024.
3. Global Investment in the Energy Transition Exceeded $2 Trillion for the First Time in 2024, According to BloombergNEF Report | BloombergNEF, 30 January 2025

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