Wider losses at Ceres Power, the fuel cell technology developer, prompted a 25% tumble in the share price. Operating loss grew to £16.7m for the year to the end of June, compared to £13.2m the year before. Revenue was slightly lower at £0.7m, down from £0.8m in 2010, but the growing losses were largely a result of rising operating costs, from £14.5m to £17.7m. Chief executive David Pummell said: "Since my appointment I have conducted a detailed review of the business and our plan to achieve mass market uptake of the group's residential CHP (combined heat and power) product. "Ceres Power has world-leading technology and a highly differentiated CHP product that is capable of mass market adoption, albeit later than originally planned. I am confident that we can successfully deliver both the revised commercialisation plan and significant value to shareholders."The group is now focusing on completing the development, trialling and launch of a low cost, durable CHP product that provides the consumer with clean, economic energy on demand. Loss per share grew from 15.16p to 16.04p.The share price fell 23.2% to 24p by 11:13.NR