Source: Associated Press

CHICAGO -- United Airlines has announced a 3 percent fare increase on most of the carrier's domestic and international flights, citing the rising cost of oil as the reason.

The Elk Grove Village, Ill.-based airline said Tuesday that the increase is effective immediately.

John Tague, United's executive vice president for marketing, sales and revenue, said the airline is confident its customers will understand the need to raise ticket prices.

"With oil continuing to trade at historically high levels, all industries must act responsibly to offset rising costs," Tague said in a written statement.

The fares have been increased by an average of 3 percent, though sale fare levels and some specialty fares are not affected by the increase, United said.

The nation's older airlines have been losing hundreds of millions of dollars, as high oil prices make fuel expensive and competition from discounters keeps fares low.

United, the nation's second-largest airline, filed for bankruptcy 2 1/2 years ago and has said it hopes to emerge from Chapter 11 this fall. But the airline, a unit of UAL Corp., still must work out new terms on dozens of plane leases and secure exit financing, among other issues.