In an order issued late Monday, the U.S. Court of Appeals for the District of Columbia Circuit says the slot auction cannot be held until a federal court rules on objections from New York airport officials and airlines.

Transportation Secretary Mary Peters called for the auction as a way to reduce air traffic at John F. Kennedy, LaGuardia and Newark airports. Peters' decision to auction slots followed widespread complaints last year about lengthy flight delays.

Airlines and the Port Authority of New York and New Jersey filed suit saying the proposal would add new costs and make a mess of day-to-day airport operations.