State-run oil firms today raised jet fuel price by 4 per cent. In the ninth straight increase in rates since October, Aviation Turbine Fuel – ATF – rates in Delhi have been hiked by 2,104 rupees per kilolitre to 53,538 rupees with effect from midnight tonight. Indian Oil Corp, the nation's largest fuel retailer said,the hike has been necessitated because of spurt in international oil rates.Jet fuel will cost 53,538 rupees per kl in Mumbai from tomorrow, as against 51,332.82 rupees.There has been no word yet from airline companies on the impact of the latest price hike on passenger fares. Fuel cost accounts for 40 per cent of the airlines' 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 the average international price in the preceding fortnight.