BEIJING, March 10 -- China National Petroleum Corporation (CNPC) said on Monday that its subsidiary has signed an agreement with Tajiktransgaz to establish a gas pipeline company.

CNPC Trans-Asia Gas Pipeline Company Limited last Tuesday in Duschanbe signed an agreement with Tajiktransgaz on jointly establishing a natural gas pipeline company to manage the construction of Line D of the Central Asia-China Gas Pipeline.

Preparation for Line D started soon after the signing of an agreement signed in November 2011 between China and Turkmenistan. The agreement aims to add 25 billion cubic meters in gas supply to China from Turkmenistan annually.

Then in September 2013, the Chinese government signed inter-governmental agreements with Uzbekistan, Tajikistan and Kyrghyzstan respectively on Line D.

The feasibility studies have been completed by Trans-Asia Gas Pipeline Company.

Construction of the Tajikistan section of Line D is expected to start within year 2014.

By the end of China's 13th Five-Year Plan period (2016-2020) when construction of the Lines A, B, C, D and auxiliary facilities in China are completed, 80 billion cubic meters of natural gas will be transported from Central Asia to China annually, taking over 40 percent of China's gas imports, according to the CNPC.