Nviro Cleantech, an investor in green technology and environmental consultant, has listed on the alternative investment market.

The move by the company, which has a market capitalisation of £27m, is a sign of the growing attractiveness of the green and renewable technology sectors to the City.

The company takes prototype designs for clean technologies such as clean coal power and biomass boilers, develops them and launches them on the market as commercial propositions. The firm, which was established two years ago, is obtaining several patents.

It has raised £7.5m through the placing, which values its shares at 63p. It will invest the proceeds in expanding its portfolio.

Chris Every, the chief executive, said: “We’re confident that our technology portfolio and flexible business model give us the necessary agility to exploit the shifting and fast growing global market for clean technologies, which has been conservatively estimated to reach £400bn by 2015.”

Its main project now is a scheme to clean low quality coal and biomass. It is also working on a technology to recycle mdf into higher quality wood fibre.