China has issued a plan to open up its largely monopolized oil and gas pipelines, in a bid to increase the efficiency of the facilities, an energy authority said on Monday.

The National Energy Administration said in the plan that it encourages pipeline operators to open their facilities to each other and to users, including fuel producers, refiners, sellers and other industrial users, when pipelines have extra capacity.

Pipeline operators are supposed to provide services including transport, storage, gasification, liquefaction and the compression of crude oil, product oil and natural gas, at a price agreed upon by the two sides.

The plan involves both onshore and offshore pipelines, and the implementation of the plan will be supervised by the administration.

The construction and operation of China's pipelines are largely dominated by major state-owned enterprises. In recent years, there has been a mounting call for the business to be opened up.

China has already begun taking measures to open up the whole oil and gas industry.

Last week, Sinopec, the country's largest refiner, proposed selling up to 30% of its multi-billion-dollar marketing arm to social and private investors, a development which experts see as a big step to restructure the sector.