Northwest Airlines and other big airlines are hiking ticket prices to offset another spike in fuel costs.

Delta Air Lines led the most recent hike of $10 per roundtrip late last week in certain markets. Others, including Northwest, followed over the weekend, according to FareCompare.com, a Web site that follows air fares.

There are 19,000 city pairs on Northwest's schedule affected by the change, the Web site says.

Other airlines that embraced the increase include United and American Airlines. And even the low-cost carriers are said to be getting on board with the increases as JetBlue and AirTran hiked fares on certain flights.

The fare increase marks the sixth so far in 2008 for the nation's airlines.

It did little to help ailing airline stocks this morning, which were trading lower as crude oil shot to a new record high.

Leading the retreat: Delta and Northwest, which continue to get kicked as merger prospects are seen as dimming. Delta shares were off 5 percent, to $12.69 while Northwest was down 5.5 percent, to $12.69 per share at noon.