In a sign of great uncertainty about demand for air travel this year amid the deep U.S. recession, discount carrier AirTran Airways launched a fare sale to all its destinations Tuesday for flights through the middle of the fall.

American Airlines and Continental Airlines quickly matched on routes where they compete with AirTran, and JetBlue said it would do the same.

AirTran's sale extends through the summer, normally a busy time for airlines, when they have been able to reap premiums in the past as more people travel. But now with many people hurting financially, fewer are taking vacations, businesses are cutting back on corporate travel and many who fly are waiting longer to book.

AirTran, a unit of Orlando, Fla.-based AirTran Holdings Inc., said its sale fares, starting as low as $39 one way, are available for purchase through March 5 for travel through Nov. 4.

New York-based JetBlue Airways Corp. will match in markets where the two carriers compete, spokesman Sebastian White said.