The 18 manufacturers of poly vinyl chloride (PVC) collaborated to raise PVC prices last year, causing obvious price hikes in the market, the National Development and Reform Commission (NDRC) said.
Their behaviour harmed the market competition order, the profit margins for downstream PVC users and consumers' interests, said the NDRC.
Each of the 18 companies was required to pay between one and two per cent of their annual revenue as a fine, state-run Xinhua news agency reported.
They reached 13 price monopoly agreements.
Hubei Yihua Group and China National Salt Industry Corporation, Jilantai Salt Chemical Group played a leading role and proposed six meetings to discuss price hikes.
PVC products are widely used in building materials as well as medical and household appliances.