Companies like Orbitz Worldwide Inc and Inc have ramped up efforts to attract customers to their sites overseas, and at least one U.S. travel site, Vayama, has devoted itself entirely to international bookings for travel to and from the United States.

Growth in bookings made outside the United States far outpaces the growth in U.S. domestic bookings. That is partly because more people are traveling and partly because travelers are increasingly comfortable trusting their reservations to Web sites, said Orbitz Chief Executive Steve Barnhart.

"It's a competitive market place in the United States, and it's going to be a very competitive marketplace globally," Barnhart said in an interview on Monday.

Earlier this week Orbitz said it has relaunched ebookers, its online travel company in Europe, with more inventory and user reviews with the goal of attracting more European bookings.

Get the full story at the International Business Times