Petrol prices across the four metro cities rose for the 12 consecutive day on Friday, but consumers can expect some respite in the coming days as global crude oil cost eased. In the national capital, price of petrol rose to Rs 77.83 from Rs 77.47 per litre on day-to-day basis. Similarly, petrol prices also rose in other major cities of Kolkata, Mumbai and Chennai, where the fuel cost Rs 80.47, Rs 85.65 and Rs 80.80 per litre, respectively, against Thursday's levels of Rs 80.12, Rs 85.29 and Rs 80.42 per litre. Prices in Delhi, Mumbai and Chennai have already reached record levels, while in Kolkata, it is inching close to a four-year-high level. However, consumers can expect some relief as the Brent crude oil prices fell to around $78 from $80 per barrel on Friday. As per the pricing mechanism, the domestic petrol prices are dependent upon the international fuel price on a 15-day average. In tandem with petrol prices, diesel prices in Delhi, Kolkata, Mumbai and Chennai also rose to fresh record highs of Rs 68.75, Rs 71.30, Rs 73.20 and Rs 72.58 per litre, respectively. On Thursday, prices in these cities stood at Rs 68.53, Rs 71.08, Rs 72.96 and Rs 72.35 per litre. Of late, geo-political tensions in the Middle East and supply side constraints have led to a surge in global crude oil prices.