Petrol prices were increased by the oil marketing companies (OMCs) on Friday in four metropolitan cities. However, rates of diesel were kept stable for a third consecutive day. In Delhi, petrol prices rose by 10 paise per litre. In Mumbai, the price of petrol witnessed a hike of 9 paise per litre. A litre of petrol was being retailed at a price of Rs. 82.32 in Delhi, Rs. 89.69 in Mumbai, Rs. 85.58 in Chennai and Rs. 84.16 in Kolkata after the latest revision, according to a price notification of state-owned fuel retailers.