Shares of oil marketing companies corrected sharply as the oil ministry today gave in-principal nod to export parity pricing model for petroleum products, which is likely to result in huge losses for these oil retailers. Following the news, shares of OMCs like Hindustan Petroleum Corp , Bharat Petroleum Corp and Indian Oil Corp went down 4-6 percent. Earlier Aakansha Sethi of CNBC-TV18 reported that Petroleum minister Veerappa Moily has agreed to price petroleum products using export parity as proposed by finance ministry to cut down government's oil subsidy burden.