US Airways Group Inc. cut some U.S. and Canadian fares as much as 45%, spurring other major U.S. airlines to offer discounts. UAL Corp.'s United Airlines, AMR Corp.'s American Airlines, Delta Air Lines Inc., Northwest Airlines Corp., Continental Airlines Inc., America West Airlines and Trans World Airlines Inc. cut fares to match US Airways, said Terry Trippler of 1Travel.com. The other airlines didn't extend their discounts to routes outside those on which they compete with US Airways, Trippler said. US Airways' cuts, which are for flights through Dec. 15, were not available the weekends before and after Thanksgiving, though there were no blackout dates for Labor Day weekend. Tickets must be bought by July 21 and at least 14 days before travel. Separately, Southwest Airlines Co. reduced fares on flights between the U.S. coasts and along the West Coast. Tickets must be bought by July 27 and at least seven days before travel. Discounts are for flights between Aug. 14 and Dec. 9. AirTran, which is operated by AirTran Holdings Inc., cut fares as much as 35%. The discount tickets must be purchased by July 18 and at least 14 days before travel. The travel must be completed by Nov. 15.