Priceline.com on Thursday offered a promotional price guarantee on airline tickets and vacations.

The promotion follows a similar deal unveiled this week by Travelocity, and a fee waiver announced last week by Expedia Inc.

Orbitz Worldwide, which launched its own price protection policy last year, plans to announce a major hotel sale on Friday.

'Downward demand pressure on a commodity business usually creates these types of price wars,' said Morningstar equity analyst Warren Miller.

The travel industry has suffered in recent months as the recession erodes travel budgets.

The companies hope to boost bookings for the peak summer travel season despite consumer anxiety about the economy. -- REUTERS