Summit and director Chris Weitz made the announcement Wednesday.
In New Moon, the Jacob Black character becomes a central figure in the plot as Bella Swan is drawn into the world of the werewolves, the ancestral enemies of vampires.
Weitz noted there has been speculation about whether Lautner could portray the character who goes through many changes physically, including growing taller and bulkier and aging 10 years. The 16-year-old Lautner has been spending time in the gym, trying to add 19 pounds of muscle.
Weitz added that Lautner is “emotionally right” for the part.
Lautner joins castmates Robert Pattinson and Kristen Stewart in New Moon, set to begin production soon for a Nov. 20 release.