BEIJING, Dec 6 (Reuters) - China"s state-backed Sinopec (600028.SS) has received government approval to expand its liquefied natural gas (LNG) receiving terminal in the northern coastal city of Tianjin, a local-government backed media reported on Monday. The expansion project will drive annual LNG receiving capacity to 11.65 million tonnes from a current 10.8 million tonnes, and includes five new LNG storage tanks with capacity of 270,000 cubic metres each.The project, the third phase of the Sinopec Tianjin LNG terminal, will further ensure gas supply to northern China and to Sinopec"s Tianjin refinery as feedstock of its 1.2 million tonnes ethylene facility, according to the Tianjin Daily report. The report did not disclose any timeline of the Sinopec project, nor its total investment.Sinopec didn"t immediately respond to Reuters" request for a comment. Reporting by Muyu Xu and Shivani Singh; Editing by Rashmi Aich