Gresham House completes SUSI Partners acquisition

Key highlights:

• Completion of the acquisition brings SUSI Partners into Gresham House, creating a top ten European energy transition infrastructure platform
• Expanded capabilities combine Gresham House’s UK market leadership in battery storage with SUSI Partners’ international mid-market equity and credit expertise across energy transition sectors
• The enlarged platform increases Gresham House’s AUM from £9.0bn to £10.7bn (€12.2bn) and extends its geographic reach into continental Europe and Asia
• Marco van Daele will lead the unified Gresham House Energy Transition division as the platform scales internationally
• The acquisition is complemented by the opening of Gresham House’s new Frankfurt office, led by newly appointed Armin Sandhoevel

Gresham House, the specialist alternative asset manager, has completed its acquisition of SUSI Partners AG (“SUSI Partners”), the Swiss-headquartered energy transition infrastructure investment manager, after securing all required approvals, taking combined assets under management (AUM) to £10.7 billion (€12.2 billion).

The integration of SUSI Partners into Gresham House creates a £2.7 billion (€3.1 billion) energy transition infrastructure platform, which ranks among Europe’s top ten largest in this segment. The enlarged platform strengthens the firm’s ability to provide, differentiated investment solutions that aim to generate impactful financial and sustainability-linked returns for clients.

Now that the transaction has completed, all of SUSI Partners’ employees have joined Gresham House. Marco van Daele, previously CEO of SUSI Partners, will assume leadership of the integrated Energy Transition division. All existing SUSI strategies – including equity, credit, and the Southeast Asia-focused strategy – will remain under the leadership of their current portfolio managers. Gresham House Managing Director, Ben Guest, will continue to oversee the UK battery storage efforts, including managing Europe’s largest listed fund strategy dedicated to investing in utility-scale battery energy storage systems, Gresham House Energy Storage Fund plc (GRID).

As part of Gresham House’s growth strategy in continental Europe, the firm has opened a new sales office in Frankfurt, which is led by Armin Sandhoevel as Managing Director, Business Development. Armin brings over 20 years’ experience in global infrastructure and climate-related investments, most recently serving as Chief Executive Officer for the Infrastructure Equity division at Allianz Global Investors.

First announced in September 2025, the transaction brings together SUSI Partners’ 15-year track record in mid-market equity and credit with Gresham House’s market-leading UK battery energy storage expertise. The combined platform offers a broadened suite of equity, credit, co-investment and bespoke mandate solutions, enabling investors to access a wider range of opportunities across the global energy transition. In 2026, the platform is launching a new global energy storage strategy, a new private credit infrastructure strategy, and an expansion of its Southeast Asia-focused energy transition strategy.

With enhanced scale and international reach, the division aims to capture value across multiple sectors and stages of the energy transition aiming to deliver long-term, resilient returns for investors.

Tony Dalwood, CEO of Gresham House, commented:

“This transaction is a major milestone for Gresham House, reinforcing our leadership in the energy transition and significantly expanding our global capabilities. Integrating SUSI Partners enables us to offer investors a broader suite of differentiated equity and credit solutions and accelerates our ability to channel capital into the technologies powering global decarbonisation. Most importantly, it will assist us in fulfilling our aim to deliver attractive, impactful returns for our clients.”

Marco van Daele, Head of Energy Transition at Gresham House, added:

“Joining forces with Gresham House brings together two highly complementary platforms with a shared ambition to lead the energy transition. With greater scale, deeper expertise and a wider international footprint, we are better positioned to meet growing investor demand in our aim to deliver compelling, impact-driven investment solutions with strong return potential.”

Media contacts

Edelman Smithfield – GreshamHouse@edelmansmithfield.com
Louis Supple – +44 (0) 7739 430102