A pitch kicked off in April and was managed by Agency Insight. It covered the car brand’s worldwide markets, which are believed to be primarily in Europe.
MediaCom, which is the global media agency for Seat's parent Volkswagen, has retained the majority of the global business, with a media spend believed to be in the region of £150 million.
However, the WPP shop has lost the UK account, which has been awarded to PHD. Seat spent £13.9 million on media in the UK last year, according to Nielsen figures.
The two-year contracts for both agencies will begin in January 2014.
A pan-European advertising review is also underway out of Grey London, which picked up the business in November 2012.
In January, Seat launched an augmented reality app for users to discover more about its new Leon car when they visit its showrooms. The app was created by digital agency Analog Folk, which was unaffected by the review.