United Airlines boosts U.S. fares; rivals follow

UAL Corp.'s United Airlines, the world's second-largest carrier, raised most U.S. round-trip fares as much as $20 to blunt a surge in jet-fuel prices.

Delta Air Lines Inc. and Continental Airlines Inc. matched the increase, and AMR Corp.'s American Airlines was studying the new fares, spokesmen for the carriers said.

If other airlines follow, the boost would be the eighth broad increase among U.S. airlines this year. Jet fuel has jumped 36 percent in 2007, pushing fuel costs ahead of labor as the biggest expense at some carriers.