After Delta Air slashed its prices by up to 50% this week, sn reported, other major airlines have followed suit. American Air, Continental, United, and Northwest have reduced prices on their most expensive routes.
Tom Parsons, chief executive of Bestfares.com, said: "As we forecasted yesterday, it took less than 24 hours for the five remaining legacy carriers to match Delta's moves."
Many carriers have also abolished most Saturday-night stay requirements in a bid to win customers away from other carriers.
The new price war could have a negative effect for the airlines in the long term say some analysts.
