October 6, 2025: Switzerland’s SUSI Partners is to be acquired by UK-based Gresham House Holdings for an undisclosed sum, in a move aimed at expanding investment in the global BESS and energy infrastructure markets.

The energy sector-focused investment firms said on September 19 SUSI’s investment strategies, products, and portfolio management teams will be combined with Gresham’s UK-focused BESS-led energy transition infrastructure division.

This will more than double the division’s size to around €3.1 billion ($3.8 billion) in assets under management. On completion of the deal, the newly combined division will be led by SUSI’s CEO, Marco van Daele.

SUSI’s portfolio management leads and teams will manage the firm’s existing equity, credit, and Asia strategies, while Gresham’s UK-focused strategies will continue to be managed by the firm’s team.

Gresham CEO Tony Dalwood said global investment in the 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 2050.

“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.”

Dalwood said the deal will also expand Gresham’s geographic reach and spur a wider range of strategies, such as co-investment opportunities.

“Together, we will be better placed to deliver financial returns by investing in the global themes shaping the future.”