Microsoft is set to step up its Windows Phone marketing campaign, building on its existing marketing featuring Gwen Stefani, Jay-Z and Jessica Alba, and tapping into The Hobbit franchise following a deal with Warner Bros.

Marketing reports that Microsoft has partnered with Wunderman to create new digital, press and outdoor materials, featuring Bilbo Baggins (played by Martin Freeman), Gandalf (Sir Ian McKellen) and other characters from first film of trilogy, directed by Peter Jackson.

Warner Bros. has agreed to license the use of the characters in the UK, US, France and Germany — perhaps the most popular markets for devices running Microsoft’s new Windows Phone 8 operating system.

Microsoft is building on “The smartphone reinvented around you” theme for its Windows Phone 8 platform, debuting TV adverts that show how different celebrities personalise and use different features on their Windows Phone devices. With The Hobbit licensing deal signed, Microsoft and its agency partner will no doubt focus on the diminutive Hobbit heroes and the grey wizard to send the same message.

At BUILD, Microsoft promised an advertising deluge in support of Windows 8, Windows Phone 8, and Surface. The company has already pushed its ‘Click in’ Surface ads, as well as the first wave of Windows Phone spots, which hit last week.

The Hobbit hits theaters on December 13, expect to see billboards, bus stops and lots of digital ads in the weeks leading up to its release.