Bungie

As Activision continues to lose members from its most high-profile development studio, Infinity Ward, the massive publisher has gone ahead and signed a 10-year deal with what will certainly be their new most high-profile development studio.

Bungie, the studio behind the "Halo" franchise, has agreed to the publishing deal which will include exclusive publishing rights of the developer's next game (after "Halo: Reach" releases this fall)

Source: http://multiplayerblog.mtv.com/2010/04/29/bungie-activision/