China may rely on imports for more than 35 percent of its natural gas supplies by 2015, up from 15 percent in 2010, according to estimates by the National Energy Administration.

Overseas purchases may rise to 93.5 billion cubic meters by 2015, based on contracts already signed, according to a document posted on the NEA's website on Monday. Domestic output is forecast to rise to 176 billion cubic meters, the agency said.