New Delhi, Sep 30: Diesel price was today hiked by 50 paise per litre but there will be no change in petrol rates.Diesel will cost Rs 44.95 per litre with effect from midnight tonight as against Rs 44.45 currently, Indian Oil Corp, the nation's largest fuel retailer, said." The current level of international prices and INR-USD exchange rate warrant a price increase, which is being passed on to consumers with this price revision," IOC said.