Bangladesh, Oct. 27 -- Jet fuel cost the US carrier an adjusted USD 3.61 a gallon during the quarter, up 60% year-on-year. Its adjusted fuel bill climbed 62% to USD 4.1 billion.

For the full year, Delta expects fuel expenses to run roughly USD 6 billion higher than last year, prompting the airline to lower its profit forecast.

Despite the pressure, the Atlanta-based carrier reported about USD 1.5 billion in adjusted pre-tax profit for the quarter, nearly matching last year's figure, and still expects around USD 4.5 billion in pre-tax profit for the full year.

Much of the cushion comes from the Trainer refinery near Philadelphia, which Delta bought from Phillips 66 in 2012 for USD 150 million, aided by USD 30 million in state assistanc...