State-owned Indian Oil Corp, IOC raised petrol price by 27 paise a litre effective midnight last night. Other public sector firms are likely to follow suit in the next couple of days. An IOC official said, petrol will now cost 51.83 rupees a litre in Delhi, 56.25 rupees in Mumbai, 55.69 rupees in Kolkata and 56.31 rupees in Chennai. The official said, the price hike has been necessitated because of rise in crude oil prices. This is the first time since the June decision of the government to free petrol price from its control, that the rates of petrol is being raised.