NEW DELHI: The PSU oil marketing companies (OMCs) may go slow in automatic pass through of rise in international crude oil prices to the consumers due to the already high cost of transportation fuel such as petrol and diesel, ratings agency ICRA. According to the ratings agency, the marketing margins of OMCs have been higher than the past long-term averages, presumably to bolster profits in a scenario of weak demand and subdued GRMs. "Faced with a global over-supply amid weak demand owing to the Covid-19 pandemic, the crack spreads of MS, diesel and ATF crashed to historic lows leading to subdued GRMs globally," Prashant Vasisht, Vice-President, Corporate Ratings, ICRA was quoted as saying in a statement. (IANS)