Hengli Petrochemical, the group's listed unit, started constructing on Tuesday in city of Suzhou a complex that makes polyester film and plastics with a combined production capacity of one million tonnes each year, the group said on its official Wechat account.
The polyester films are used in packaging, automobile and electronics sectors and the high-end plastics can be used to make biodegradable bags and in 3-D printing.
Hengli will build under the first phase a 800,000 tonne per year plant expected to be complete in about 30 months, a company representative said.
Hengli Petrochemical also operates one of China's single largest refineries in the northeast port city of Dalian, with a daily crude oil processing capacity of 400,000 barrels.
($1 = 6.4423 Chinese yuan renminbi)
(Reporting by Chen Aizhu, editing by Louise Heavens)