Indian Oil Corporation-IOC today reduced the petrol price by 56 paise per litre. The new rate will be efective from midnight tonight. According to a statement, petrol in Delhi will now cost 67 rupess and 90 paise per litre against the earlier price of 68 rupees and 46 paise. While in Mumbai the price will be 74 rupees and 43 paise, in Kolkata, it will be 75 rupees and 44 paise a litre and in Chennai, it will cost 71 rupees and 48 paise per litre. The reduction in petrol prices follows appreciation of rupee value against the US dollar.IOC said the trends in the international oil market and exchange rate would be closely monitored and would be reflected in future price changes.