While most airlines are caught in a downdraft these days, online travel agencies are enjoying a much smoother ride.

Several major airlines reported grim second-quarter earnings this week, and executives said a turnaround is not likely anytime soon. On Thursday, Delta announced a second-quarter loss of $90 million, compared with a profit of $460 million a year earlier. Northwest Airlines posted a $55 million loss and said it will cut 1,500 jobs. On Wednesday, AMR, the parent of American Airlines, posted a whopping $507 million loss in contrast to a $321 million profit last year.

Online travel agencies are faring much better. While overall travel spending is down, Internet firms such as Travelocity and Expedia are grabbing a larger share of the overall market. Online travel sales are expected to grow 40 percent this year to $24 billion, according to Forrester Research.

Online agencies typically have focused their businesses on finding passengers the best airfares, but they are increasingly diversifying from that low-margin model into more-profitable products such as vacation cruises and packages. On Wednesday, Travelocity posted a profit before special items of $1.8 million (8 cents per share), up from last year's pro forma loss of 22 cents before certain charges. Revenues increased 76 percent to $82 million thanks to an increase in the sale of packages.

"We sold more cruises and vacation packages during the first half of the year than we did during all of last year," said Travelocity CEO Terry Jones.

Jeff Jackson, CFO for Travelocity's parent company, the Sabre Group, said profit margins on vacation packages can reach 20 percent to 25 percent, compared with the 10 percent profit margins on more typical airline bookings by agents. He said selling packages also attracts a broader base of customers and makes Travelocity "less vulnerable" to fluctuations in airline traffic and prices.

Travelocity's growth injected some life into its parent company, which is growing increasingly reliant on Internet sales as the travel business moves away from Sabre's proprietary computer reservation system. Travelocity accounted for 44 percent of the $80 million increase in revenues it posted for the quarter ending June 30. Total revenues were $582 million.

Expedia, the No. 2 online travel site, said earlier this week that it expects revenue for the fourth quarter ending June 30 to be $78 million, up 37 percent from $57 million the previous quarter. CEO Richard Barton attributed some of the company's revenue growth to increased sales of vacation packages.

While the sale of packages over the Internet is off to a good start, it does face obstacles – in particular the consumer habit of booking airline tickets separately from hotel rooms and sometimes even cruises. "We're used to buying our travel a la carte," said Lorraine Sileo, an analyst at PhocusWright, a travel consultancy.

But these days, any buying is good buying, and online travel agents are thrilled that more of it is coming their way.