Atlanta-based Delta Air Lines and Air Train Airlines face fines for false advertising.
The penalty comes from the U.S. Department of Transportation.
The DOT says in February Air Tran advertised on its website flights for $39 as part of the “Leave the Blizzard Behind Sale.”
But DOT investigators say the lowest available fare was $44.
The company will pay $20,000 for the violation.
The fine against Delta is for the carrier’s failure to disclose extra taxes and fees included with on-line ticket sales.
Delta will pay $40,000 in fines.