Oil companies have raised jet fuel price by a massive four per cent, the ninth straight increase in rates since October. The Aviation Turbine Fuel (ATF) rates in Delhi have been hiked by Rs 2,104 per kilolitre, or 4.12 per cent, to Rs 53,538 per kl with effect from midnight 15 February by Indian Oil Corp. The hike, the second biggest in a year, comes on the back of another 4.5 per cent jump in rates effect from 1 February. IOC officials cited spurt in international oil rates necessitating hiked prices. In Mumbai, jet fuel will cost Rs 53,538 per kl as against Rs 51,332.82 per kl earlier. Fuel cost accounts for 40 per cent of the airlinesâ€™ operating cost. Indian Oil Corp and sister public sector retailers Bharat Petroleum and Hindustan Petroleum revise jet fuel prices on the 1st and 16th of every month, based on average international price in the preceding fortnight.