Petrochemical Corporation of Singapore (Pte) Ltd started as a joint venture between the Government of Singapore, The Development Bank of Singapore Limited and the Japan-Singapore Petrochemicals Company Limited (JSPC). The present shareholders are JSPC (50%) and QPI and Shell Petrochemicals (Singapore) Pte. Ltd. (50%).

As the upstream company of the Singapore Petrochemical Complex, PCS' main role is to supply high quality ethylene, propylene, acetylene, butadiene, 1-butene, MTBE and benzene. It also supplies utilities such as water, steam and compressed air to downstream companies that in turn produce high quality petrochemical products for their customers. In addition, PCS produces toluene and xylene, which are exported to the Southeast Asia region and beyond for further processing.

PCS also provides common facilities and services such as berths, security and fire fighting services to ensure the efficient and safe operation of the Complex. In short, it coordinates the supporting activities necessary for the efficient operation of the entire Complex.