PetroChina Co, Asia's largest oil and gas producer by market value, disclosed yesterday that China's new natural gas transmission pipeline project will have investment from private companies.

However, analysts said that "only opening" China's petroleum and gas sector, which has long been dominated by State-owned companies, "is not enough."

Jiang Jiemin, chairman of the State-owned PetroChina, announced yesterday at a media briefing that construction of China's third west-east natural gas transmission pipeline is to start this year and will be completed in two to three years.

The pipeline will carry natural gas from Turkmenistan and Northwest China's Xinjiang Uyghur Autonomous Region through 15 of the country's province-level regions to the Yangtze and Pearl River deltas, the country's two most economically developed regions.

Investment in the project is expected to reach more than 100 billion yuan ($15.8 billion).

"Investment from the government as well as from other sources, including private capital, will be introduced," Jiang said. He noted that more detailed information will be announced by the end of June.

In 2010, China's State Council announced that the government would encourage private capital to enter sectors controlled mainly by State-owned companies, including the petroleum and gas sector.

However, according to a notice released by the Ministry of Land and Resources, Sinopec and PetroChina, the country's top refineries, still own the exploration rights to 291 of the country's mining areas for petroleum and gas, accounting for 89.2 percent of the total. Privately owned companies only have exploration rights to four mining areas, with the rest owned by local governments or other State-owned companies.

"Just opening the industry, which can certainly encourage competition, is not enough," Lin Boqiang, director of the Center for Energy Economics Research at Xiamen University, told the Global Times yesterday.

Lin noted that the State-owned companies usually possess advantages, and they can endure losses for a long time. Therefore, the competition between them and privately owned companies is "unfair."

"Encouraging their (privately owned companies) engagement in the energy sector calls for solid supportive policies from the authorities," said Lin.

Jiang of PetroChina said the company will import 23 billion to 25 billion cubic meters of natural gas from central Asia this year, up from the 15.9 billion cubic meters in 2011.

He also said gas imports were one of the main reasons for PetroChina's operating losses.