It said proceeds from the offer would fund the development and sale of its fuel cell products. The Surrey-based company plans to develop fuel cells for use in home boilers to provide cheaper and more environmentally friendly heating and electricity for the home.

"It's at a commercial price point which we think we can hit and be directly competitive with existing technologies, that's in a sense our killer application," Peter Bance, chief executive, told Reuters.

Fuel cells have been touted as environmentally sound electricity producers that could replace fossil fuels such as coal, oil and natural gas as the world's primary energy source.

They operate by generating electricity through a chemical reaction that leaves water and heat as byproducts. Other companies are developing the technology to produce fuel cell-powered cars.

Ceres shares were trading at 135 pence at midday, up 15p from their issue price of 120p, on volume of 3.2 million shares. Numis Securities handled the flotation.

Ceres is the latest in a steady flow of new listings on the London Stock Exchange's junior AIM market this year, although the pace of bigger arrivals has dried up since a flurry of activity in the summer.

The value of another fuel cell firm ITM Power has risen to 67 million pounds, up 40 percent since listing on AIM in June. But yet another peer, Intelligent Energy, scrapped plans to float due to weak demand for its shares.

The fragile appetite among investors for new issues has forced a number of firms to shelve plans to list, although London has attracted more new arrivals than most European markets.

Several firms are lined up to make sizeable debuts in London next week, including fund manager Dexion, which has raised 83 million pounds ahead of its main market listing on Monday.