CHEVRON Corp confirmed it has begun exploring for shale gas in China, joining other global giants in developing deposits in the world's largest holder of the unconventional fuel.

"The company signed a joint study agreement to explore for natural gas from shale resources in the Qiannan Basin in April 2011 and commenced seismic operations in July 2011," Chevron said in a Thursday filing to the United States Securities and Exchange Commission.

The US oil producer didn't identify its Chinese partner but Chinese media have reported it's a unit of Sinopec. The Qiannan Basin is in Guizhou Province in southwest China.

China is bringing in foreign technology to speed up the development of its shale gas reserves, believed to be the world's largest.

Royal Dutch Shell Plc has been developing shale gas in southwest China's Sichuan Province with PetroChina Co while BP Plc has a joint program with Sinopec in Guizhou.

Shale gas has become a game changer in the US thanks to improvements in technology.