The incumbent agency on the account had been McCann Erickson, part of the Interpublic Group.
The move is the second major Microsoft win for WPP and loss for IPG after the software multinational shifted its global direct marketing brief out of MRM into Wunderman.
JWT joined the Microsoft roster around a year ago and now handles a number of key accounts including the new Google and Yahoo! search engine rival Bing.
Separately, Microsoft recently announced it is bidding to boost its advertising sales via the creation of two new teams to handle relations with brand marketing chiefs and agencies http://www.marketingweek.co.uk/news/microsoft-creates-new-ad-teams/3001835.article
The move coincided with its appointment of Publicis Groupe to help it improve the targeting of its online and TV advertising. The deal was announced by new global accounts senior vice president Greg Alright in Cannes last week.http://www.marketingweek.co.uk/news/microsoft-signs-deal-with-publicis-groupe/3001812.article