The review follows the recent appointment of Naked Communications to work on its communications strategy.
A spokeswoman said that the media review was part of an ongoing review of its agencies. She added that MPG would be invited to repitch for the account once a shortlist was drawn up. It is understood that the media auditor Billetts has been appointed to assist in the review process.
The creative account, handled by Clemmow Hornby Inge since the beginning of the year, is not affected. CHI defeated Wieden & Kennedy, Campbell Doyle Dye and the incumbent, Euro RSCG Wnek Gosper, to win the creative brief.
Expedia has attempted to position itself as a website that offers more than just flights and is trying to get consumers to use it as more of a comprehensive holiday website.
CHI created a large marketing campaign for a January sales promotion, involving price reductions and holidays, flights, car hire and accommodation.
This involved TV, radio, press, outdoor and online activity.
Expedia launched in October 1998. Its main shareholder, Microsoft, sold its stake last year to the owner of Ticketmaster, USA Interactive.