China's first spot trading center for natural gas officially opened in Shanghai on Monday. Officials said this is a milestone in energy pricing reforms.

The trading center began as a trial project in July, and now accounts for 8 percent of the natural gas trade in China. The center's trading volume is expected to reach 30 billion cubic meters this year.

China's top three oil producers, CNPC, CNOOC and Sinopec, make up 95 percent of the natural gas trading.

Officials are urging the companies to work towards reaching a market price via the trading center.