BEIJING -- Construction work on the fourth pipeline of a mega power transmission project that transports natural gas from China's western regions to the country's east kicked off Wednesday.

With a total length of 3,340 km, the pipeline runs from Wuqia county in Northwest China's Xinjiang Uygur autonomous region to Zhongwei city in Ningxia Hui autonomous region.

Upon its completion, the pipeline will boost the mega power transmission project's annual capacity up to 100 billion cubic meters, said Zhang Wei, board chairman of the China Oil & Gas Piping Network Corporation, the construction company.

The company is promoting the construction of oil and gas pipeline network infrastructure to ensure the energy security of the country, Zhang added.