Dr. Joseph Pepe and Dr. Joanne Conroy

Dr. Joseph Pepe, CEO of GraniteOne Health, and Dr. Joanne Conroy, CEO and president of Dartmouth-Hitchcock Health, discuss on Wednesday how the two health-care organizations plan to combine their organizations and expand health services.

MANCHESTER — Two of the state’s largest health-care systems — overseeing Catholic Medical Center and Dartmouth-Hitchcock Medical Center — want to combine forces into a $2.7 billion-a-year organization designed to expand patient services within the state.

Officials stopped short of calling it a merger, saying the more than a half-dozen hospitals involved would retain their own names and local leadership under the combined system, Dartmouth-Hitchcock Health GraniteOne.