This comes in the wake of a product exchange contract between Delta's subsidiary Monroe Energy and BP, which was terminated at the start of July.
Delta has said that it has replaced BP with another, as yet unnamed, party. The airline added that the termination was early, but it did not say when the contract had been due to expire.
When Delta bought the 166,000 barrel per day Philadelphia refinery in mid-2012, it struck several agreements to supply crude and buy its refined products, thereby reducing its need to trade directly in the oil market. One of those was a multi-year agreement with BP, which was to buy some of the refinery's non-jet fuel products, such as gasoline and diesel, and sell jet fuel back to Delta. It struck a similar deal with Phillips 66 to swap Trainer's refined products for more jet fuel.
The SEC filing made no mention of another agreement from 2012, that of a three-year deal under which BP was to supply crude oil to the refinery.