PetroChina Co. Ltd., the country's top gas producer, plans to step up construction of liquefied natural gas (LNG) filling stations in Chongqing Municipality as part of efforts to encourage local use of LNG-powered vehicles.

PetroChina aims to build 75 LNG filling stations in Chongqing by 2020 with total fuel storage capacity of 52 thousand cubic meters (Mcm), PetroChina said in a statement issued on Friday.

A dearth of filling stations in China is hindering the central government's attempts to boost vehicular LNG consumption, said Yu Qing, a researcher with Canadian natural gas engine manufacturers Westport Innovation Inc.

Four LNG filling stations in Chongqing opened by PetroChina during the second quarter this year have sold a combined 66 Mcm as of Tuesday, generating sales of RMB 3.09 million ($489,100).

The first station completed construction at the start of May and entered operations the same month, while the rest started up in June.

PetroChina also plans to expand use of LNG in offshore transportation, with the aim of launching a LNG-powered vessel in Chongqing before the end of this year. In addition, the company will cooperate with Chongqing Hengtong Bus Co. Ltd. and Chongqing Transportation Group to retrofit 400 to 600 vehicles to use LNG before the end of this year.