UAL Corp. , parent of United Airlines, on Monday said it withdrew a business fare increase it initiated last week.

The parent of the No. 2 U.S. carrier had raised fares by $5 for one-way trips and $10 for round trips. The increase had applied to United's first-class seats and to seats booked seven or fewer days ahead of flights.

A UAL spokeswoman did not offer a reason for the airline's withdrawal of the fare increase.

AMR Corp. , parent of American Airlines, said on Monday that it had matched UAL's increase, but rescinded it on Saturday. Northwest Airlines Corp. said it did not match the increase.

U.S. airlines, battered by low-cost competition, have initiated several lasting fare hikes lately, offsetting soaring fuel prices and bolstering revenue. For a fare hike to last, it generally must be matched by competitors.

Shares of UAL were down 3.62 percent at $23.98 on Nasdaq.