TSOC was established in June 2005 as a closed joint stock company in which Sahara owns 32.55%, GOSI owns 7.00% and the remaining 60.45% is owned by Tasnee, Tasnee Petrochemicals and Marketing Company, National Gulf Company for Petrochemical Technology and National Worldwide Industrial Advancement Company. 

TSOC was established as a holding company for investments in certain other joint venture projects.  Its current holdings comprise a 75% equity stake in SEPC and a 65% equity stake in SAAC.