ReEnergy shares have been placed with institutional and other investors at 75 pence each and trading is scheduled to start on the Alternative Investment Market on Friday, the company said. ReEnergy's main areas of focus include water desalination and processing waste into a fibre that can be used for building products or power generation.
ReEnergy's Executive Chairman Roger Hewitt said the float was an important step in building a waste management, sustainable energy and water treatment business.
"The funds raised will allow the group to maximise the significant opportunities in these core markets, all of which are increasingly coming under the scrutiny of international regulation," he said.
The company said the float would also help it to invest in renewable energy opportunities in Britain and abroad.
Cenkos Securities is acting as broker to ReEnergy and Strand Partners has been appointed its nominated adviser.