China allows more companies to explore for shale gas

China is expanding its search for more sources of shale gas, by awarding exploration licences to 16 companies.

China's rapid economic industrial growth has driven demand for energy and the government hopes to find new reserves of gas.

Production of shale gas is a huge industry in the United States, but according to some predictions China could be the world's biggest producer of natural gas by 2030.

Tony Regan, from Tri-Zen International, an energy consultancy, has been telling the BBC's Asia Business Report how China's estimated resources of gas compare with those in the United States.