NEW YORK — United Airlines, the second-largest U.S. carrier, raised most domestic airfares by 3 to 5 percent Thursday as it struggles to cope with soaring fuel costs.

The widespread fare increase is the third in a row initiated by Chicago-based United in just over two weeks. The last two attempts were quickly matched by competitors and remain in place in many markets.

The move comes just two days after Delta Air Lines Chief Executive Richard Anderson said domestic carriers will need to raise tickets 15 to 20 percent just to break even at existing fuel prices.

United spokeswoman Robin Urbanski said the carrier's latest increase is "part of our effort to pass on increases in our commodity costs that will help offset the significant and rapid rise in fuel."