American Airlines (AMR), Delta Air Lines Inc. and Continental Airlines Inc. (CAL) have raised many U.S. fares by $10 per round trip, including business fares and advance-purchase tickets bought by leisure travelers.

A leading Wall Street analyst predicted that unlike a failed effort to raise prices last week, the newest fare increase will stick.

American and Delta led the latest increase on Thursday night, generally avoiding routes where the carriers compete with low-cost airlines. At the same time, American cut fares to and from the Dallas area to compete with a fare sale announced Wednesday by Southwest Airlines Co. (LUV).

If Thursday night's increase sticks, it would be the 22nd broad fare increase by U.S. airlines in the past two years, said Jamie Baker, an analyst with J.P. Morgan (JPM).

Low-cost carriers have balked at some fare increases, occasionally causing the older traditional airlines such as American and Delta to rescind increases. But this time, most of the increases are on routes not flown by the discount carriers, meaning they can't play spoiler, Baker said.

As a result, Baker gave the latest fare boost "a high probability of success."

Neither American nor Delta immediately returned calls for comment. A Continental spokeswoman confirmed that the Houston-based carrier had matched fares on routes where it competes with the other two.

Last week, UAL Corp.'s (UAUA) United Airlines had to back off an announced fare increase after some carriers balked.

In Dallas, it's a different story. American on Thursday cut fares as low as $39 one-way to and from the Dallas area in response to a fare sale announced Wednesday by Southwest.

American's lowest prices Thursday apply to flights between Dallas and nearby cities such as Austin. The lowest one-way fares, based on advance purchase of round-trip tickets, rise to $79 or $89 to more distant cities such as Philadelphia and Las Vegas.

American and its American Eagle regional airline fly out of Dallas-Fort Worth International Airport and Dallas Love Field.

A new federal law relaxed restrictions at Love Field, allowing Southwest to sell tickets for one-stop travel between Dallas and far-flung U.S. cities. Since then, Dallas-based Southwest and American Airlines, a unit of Fort Worth-based AMR Corp., have waged a fare war for North Texas travelers.

Both airlines limit the number of seats sold at the cheapest prices.