Ecofin US Renewables Infrastructure (RNEW ), one of the smallest London-listed funds vying to exploit the energy transition, has been hit by the resignation of its three fund managers.

The £119m investment trust, which was only launched in December 2020, said Jerry Polacek, Matthew Ordway and Prashanth Prakash, who worked for Ecofin Advisors in Leawood, Kansas, had quit yesterday to ‘pursue a new venture’.

With the 5%-yielding income fund fully invested in seven, long-term US solar assets, the board said it had been reassured the portfolio would continued to be run by Ecofin’s dedicated asset management team in Overland Park in Kansas, led by Jason Benson with the support of David Sifford and his private sustainable infrastructure team.

Ed Russell, Ecofin’s senior managing director, would continue to provide overall leadership of the US fund management business.

Analysts, however, were concerned by the exodus, saying the three, who had previously co-founded Energy & Infrastructure Capital, were responsible for deal flow and sourcing the fund’s future investments.

They said RNEW had struggled to achieve scale after the $125m flotation fell short of its $250m target. In May the managers said they were considering investing in two more projects worth $51m, out of a total potential pipeline of $3bn, but the company only subsequently raised $13.1m in a share placing at $1.015, short of its $25m target.

Today the shares eased 1% to $1.02 on a 6% premium to net asset value (NAV). Despite the lack of take-up by investors, performance has been good as energy prices and inflation have soared, pushing up total NAV 20.5% in the past 12 months to give a 25.6% total shareholder return.

Stifel analyst Iain Scouller resumed coverage of the stock, cutting the broker’s previously ‘positive’ recommendation to ‘neutral’ due to the manager uncertainty and expensive share price premium.

‘The resignation of a number of portfolio managers is surprising and disappointing, with the team appearing to be setting up a new venture… We will await to see who is appointed as lead managers in the next few weeks,’ he added.

Markuz Jaffe, analyst at Peel Hunt, RNEW’s broker, placed his ‘outperform’ rating under review as he awaited an update.

Numis analyst Colette Ord said: ‘Compared with the broader renewable investment companies space, 10 of which target UK and European markets, US-focused funds have struggled to capture investor attention, despite offering exposure to long-term contracts, rather than merchant revenues.’

Ord said RNEW’s high rating contrasted with US Solar Fund (USF ), a £244m portfolio of six solar assets languishing on a 13% discount despite similar underlying returns.