Sledgehammer Games have been mentioned in relation to the Call of Duty-franchise before, but according to the LA Times the studio is actually directly involved in making Call of Duty: Modern Warfare 3 together with Infinity Ward. According to the magazine's sources, the two studios are equally sharing the development duties of the singleplayer campaign of the game, with Raven Software (Singularity) taking care of the multiplayer.
The move, it is said, is causing some problems for Activision - Sledgehammer have had to delay their own Call of Duty-game because of this. And, as we know, getting a Call of Duty-game out every year is important to Activision's strategy for the series.
The publisher has not commented on the LA Times-piece.