CHENGDU -- China will encourage investment from various sources into the exploration and development of shale gas, an official said on Sept 25, as the world's second biggest economy seeks to diversify its energy sources.

Enterprises without qualifications for shale gas exploration can join tenders for exploration projects in cooperation with qualified ones, said Che Changbo, deputy head of the oil and gas resources strategic research center of the Ministry of Land and Resources, at a forum here.

He said competition will be fully introduced in the development of shale gas, adding that the government will speed up making laws on managing the resource and improve technological standards on its exploration and development.

Shale gas is an important unconventional source of natural gas. Most of China's shale gas reserves exist in the country's South and Northwest.

China has 36 trillion cubic feet (about 1 trillion cubic meters) of exploitable shale gas, outstripping the United States, according to a 2011 report by the US Energy Information Administration.

The government should boost investment in scientific research as China lacks key technologies to develop shale gas, said Che.

China aims to diversify its energy sources and save more energy as its economy forged ahead with an annual rate of 9.5 percent in the second quarter of this year.

The government plans to cut energy consumption per 10,000 yuan ($1,563) of gross domestic product (GDP) by 16 percent in the 2011-2015 period.