Six airlines match Southwest's $10 fare hike By Hugo Martín, Los Angeles Times September 14, 2012 Airfares have inched up again. Six of the nation's largest airlines on Thursday raised their fares $10 per round trip on many routes. The fare hike was initiated the day before by Southwest Airlines, the nation's largest domestic carrier. Southwest raised its prices on about 400 of its routes, or 10% of its flights. A Southwest spokesman said the increase was "due to the challenging environment of volatile fuel prices." American, Delta, US Airways, JetBlue and Virgin America all matched the hike on a limited number of flights. United Airlines tacked the hike on a broader range of routes than the others, according to Farecompare.com, a website that keeps track of airline ticket prices. Rick Seaney, founder of the website, suspects that the fare hikes were on the most popular routes because passengers might stop flying the less-popular routes if prices were to go up. Just last month, Southwest initiated the last widely adopted hike, a $10 increase for round trips of less than 500 miles. It was matched by major carriers. Fare hikes typically are initiated by one of the major airlines. If most of the airline's competitors match the increase, the fare hike remains. If not, the airline that initiated the hike usually rescinds it within days. So far this year, airlines have launched 11 fare hikes - six that were matched and five that were rescinded. Last year, 22 fare hikes were initiated by various airlines but only 12 were matched by most of the carriers.