American, United Raise Fares $20 in Second Increase This Month

American Airlines and United Airlines raised most domestic fares by as much as $20 for a round trip, the second increase in as many weeks, as they try to take advantage of peak U.S. summer travel season demand.

AMR Corp.'s American boosted prices by $10 to $20 on most U.S. routes yesterday, and UAL Corp.'s United matched the move, ticket-research firm FareCompare.com said in an e-mail. Delta Air Lines Inc. and Southwest Airlines Co. led carriers in a $20 round trip increase in the second week of June.

Airlines are raising ticket prices after traffic plunged for 12 straight months as business travelers curbed spending in the recession. Carriers are trying to make up for a 59 percent jump in fuel prices since a 12-month low on March 11 of $1.15 a gallon.

Robin Urbanski, a spokeswoman for Chicago-based UAL, said the carrier increased fares. Fort Worth, Texas-based AMR didn't immediately return a message seeking comment.