New Delhi, Oct 23 : Retail prices of petrol and diesel remained unchanged on Friday as softer global crude and product prices prevented Indian oil marketing companies from carrying out any revision in prices. Petrol prices now are unchanged for 31 days and diesel prices for 21 consecutive days. Petrol was priced at Rs 81.06 per litre in Delhi and sold in Mumbai, Chennai and Kolkata at Rs 87.74, Rs 84.14, and Rs 82.59 per litre respectively. Diesel prices in Delhi, Mumbai, Chennai and Kolkata were Rs 70.46, Rs 76.86, Rs 75.95, and Rs 73.99 respectively. Oil sector experts said that since global oil prices were under pressure from slowing demand amid the second wave of Covid-19 pandemic across several western countries, global crude prices could fall in coming days. If this situation holds for a week or so, there could be positive gains for auto fuel consumers in India by way of a fall in retail prices of petrol and diesel. Global crude prices are holding close to $42 a barrel now. The prices were hovering between $40-42 a barrel for over a month now. But with lower oil demand and rising inventory, there is fear among oil-producing companies that crude prices may start to fall again. /IANS