State-owned oil firms have raised aviation turbine fuel, ATF price by 3.5 per cent. An official of the Indian Oil Corporation, the nation's largest oil firm, said in New Delhi that Jet fuel or ATF rates in the capital were raised by 1,325 rupees per kilolitre to 39,307 rupees per kilolitre with effect from midnight last night. In Mumbai, the rates were raised by 1,380 rupees to 40,547 rupees per kilolitre.Jet fuel constitutes roughly 40 per cent of the operating cost of an airline and the latest increase in fuel rates would put extra burden on Indian carriers.