Mainland companies involved in so-called green technology, new media, communications, and e-commerce sectors led this year's ranking of the country's fastest-growing hi-tech enterprises, according to Deloitte. The global consulting firm yesterday said the top-ranked companies named in its annual Technology Fast 50 China programme were United Cleaning Technology, Guodian United Power Technology, AdChina, Beijing LOIT Technology, and Beijing Jingdong Century Trading. It estimated the five enterprises recorded a three-year revenue growth from 1,813 per cent up to 7,744 per cent, which resulted in the group posting an average revenue increase of 3,711 per cent. The average three-year revenue growth for all 50 companies in the survey was 967 per cent, roughly the same level as last year, according to Deloitte. William Chou, the national managing partner for Deloitte China's technology, media and telecommunications group, said the leading hi-tech firms reflected the emerging sectors in the country's rapidly-developing economy. 'Foreign investors are increasingly interested in these companies,' he said. First-ranked China United Cleaning Technology, which specialises in crystalline silicon solar cells, and second-ranked wind turbine maker Guodian United Power represent the mainland's push in developing green technology that could drive the country's future growth and lessen its reliance on Western markets. Earlier this month, the mainland rejected allegations that it was handing out more than US$216 billion worth of illegal subsidies to green technology makers in a bid to dominate the sector. A survey published in May by the United Nations Economic and Social Commission for Asia and the Pacific identified the mainland as the world's biggest investor in the development of clean energy. Established in 2005, the Deloitte programme covers hi-tech companies on the mainland and Hong Kong. Most of this year's fastest-growing enterprises were located in Beijing, Shanghai, Guangzhou, Shenzhen and Hong Kong, similar to results in the last two years.