Oil marketing companies (OMCs) are facing mounting pressure as a sharp rise in crude oil prices has pushed marketing margins on petrol and diesel into negative territory, while losses on domestic LPG have widened, according to rating agency ICRA. The agency estimates that OMCs are currently incurring negative margins of Rs 8 per litre on petrol and Rs 9 per litre on diesel, with domestic LPG under-recoveries at around Rs 300 per cylinder in September.