Bungie Studios, the creator of the successful Xbox-based Halo series, will be leaving Microsoft, confirming rumours that started almost one week ago. 

Microsoft will retain an equity interest in Bungie, at the same time continuing its long-standing publishing agreement between Microsoft Game Studios and Bungie for the Microsoft-owned “Halo” intellectual property as well as other future properties developed by Bungie.
Halo 3 achieved $300-million in global sales in its first week.  Released in South Africa on 26 September, it is the fastest-selling video game ever and already one of the most successful entertainment properties in history.
“Our collaboration with Bungie has resulted in ‘Halo’ becoming an enduring mainstream hit,” says Shane Kim, corporate vice-president of Microsoft Game Studios.
“While we are supporting Bungie’s desire to return to its independent roots, we will continue to invest in our ‘Halo’ entertainment property with Bungie and other partners, such as Peter Jackson, on a new interactive series set in the ‘Halo’ universe. We look forward to great success with Bungie as our long-term relationship continues to evolve through ‘Halo’-related titles and new IP created by Bungie.”
Harold Ryan, studio head for Bungie, adds that the new relationship with Microsoft will let the company expand creatively. One of the main benefits will be the ability to wriet games for platforms other than the Xbox.