The expansion project aims to boost SSTPC's ethylene annual capacity to 1.3 million tonnes from 1.0 million tonnes.
The report, however, did not mention when the expansion project is expected to be completed.
SSTPC is a Tianjin-based petrochemical firm jointly set up by China Petroleum & Chemical Corp and Saudi Basic Industries Corp (SABIC) in 2009.
China, the world's top chemicals consumer, is building and planning a total of 15 ethylene complexes before 2023, in the biggest wave of petrochemical expansions in its history.
(Reporting by Min Zhang, Shivani Singh and Beijing Newsroom; Editing by Rashmi Aich)