Incumbent Arnold Interactive, part of the Havas group, will repitch for the account. A shortlist of agencies has been drawn up by the Advertising Agency Register, which is handling the review.
A spokesperson for Expedia, one of Europe's top three online travel firms, said the pitch would not affect other roster agencies.
The review follows a year of repositioning for Expedia, which in April launched a £12m advertising campaign by Clemmow Hornby Inge. The ads, which introduced the strapline 'Create your perfect trip', were designed to establish the company as a one-stop shop for all holiday-related services.
The campaign aims to attract business from the increasing number of consumers who prefer to browse a range of websites to purchase the various elements of their holidays.
Last June, Expedia hired Naked to work on its brand communication strategy, and in August Media Planning Group lost the media planning and buying account to PHD.