Several major U.S. airlines are once again attempting to raise prices on domestic flights.

Delta Air Lines confirmed on Friday that it had raised fares to locations like Las Vegas, Phoenix, and several Florida destinations by up to $10 per round trip.

Meanwhile, JetBlue said that it raised fares on a myriad of U.S. routes by $6 per round trip. US Airways matched JetBlue's fare hike.

Ticket prices do vary by route and time of day and while airlines raise some fares, they often cut others.

US airlines imposed about 10 broad fare increases in 2011.

Airlines typically increase fares to meet demands, and a successful fare increase can help airlines' stocks. While there have been some successful fare hikes this year, an equal number have failed as some carriers declined to go along with the higher prices. These maneuvers depend on the industry's leading carriers joining together.

Airfare-hike attempts stick when the bulk of domestic airlines match within a few days - otherwise they are forced to roll back as their ticket prices become uncompetitive, FareCompare CEO Rick Seaney said on the travel advice site.

Airlines are in a position to raise price. By cutting the amount of flights, they can fly fuller planes. These higher ticket prices show a strong sign of demand to airline investors looking to turn a profit.

Most analysts and investors have been surprised at how well the airline industry has managed its capacity this year, Helane Becker, an analyst with Dahlman Rose & Co., told Reuters.

Passengers looking for a deal during the holiday season should book as early as possible, before fares have a chance to increase anymore. The last-minute deal usually doesn't apply to holiday travel and waiting can often mean being left without a seat.