Norris McLaughlin & Marcus, among New Jersey’s largest homegrown firms by head count since acquiring a 37-lawyer Pennsylvania firm six years ago, has installed a new chairman for the first time in four decades.

Matthew Sorrentino came over in the 2009 merger with Tallman, Hudders & Sorrentino of Allentown, Pa., and now has taken over for G. Robert Marcus, who’s been chairman since 1974.