Delta and US Airways "will not go forward" with a slot swap at Washington National and New York LaGuardia airports if DOT imposes conditions

. The airlines were responding to a tentative U.S. Department of Transportation decision to allow the slot exchangeonly if Delta and US Airways agree to divest 14 pairs of slots at Washington National and 20 pairs at LaGuardia. Without such remedies, the proposed transaction at "two of our countries most congested and prominent airports … would result in a substantial increase in market concentration that would harm consumers," according to DOT. The department for 30 days will accept public comments on its tentative ruling.