London's Alternative Investment Market will be the destination of choice for clean energy companies coming to market during the next three years, according to a survey of institutional investors by Jefferies, a US mid-market specialist investment bank.

The report, which surveyed 70 institutions and hedge funds representing about €200bn ($256bn) in assets, found 57% believed London's junior market would be the most important exchange for the sector. The second most popular choice, Nasdaq, scored only 28%, while 15% thought such companies would pick local exchanges. Bruce Huber, a managing director at Jefferies and head of technology investment banking, said an arduous US regulatory environment is sending clean technology groups seeking listings to London. He said: "Aim has become the global growth capital market exchange of choice, thanks to a light-touch regulatory regime in comparison to Nasdaq, and London has a long-standing familiarity with the energy sector." More than $5bn (€4bn) has been invested in clean technology venture capital and private equity since the beginning of last year, according to Jefferies. The survey found investors view solar and wind companies as the most attractive long-term investments, with nearly half of managers picking them. The next most popular was investment in fuels companies, followed by energy-efficiency technology. US groups are coming to the London markets. On Friday, Eneco, US clean technology group, chose Aim for a £1.5m (€2.2m) European share placing and in September Seattle-based liquid natural gas producer Prometheus Energy made a $50m debut on the small-cap market. Interest has been growing in the sector. More than 80% of managers in the Jefferies survey believed investment in alternative energy funds would go up by more than half in the next three years.