A mill for use in a wellbore includes a tubular housing having a bore therethrough and a plurality of eccentrically arranged pockets formed in a wall thereof and an arm disposed in each pocket. Each arm has a body portion and a blade portion extending from an outer surface of the body portion and is movable between an extended position and a retracted position. The mill further includes cutters disposed along each blade portion and a block disposed in each pocket and connected to the housing. Each block has a guide engaged with a mating guide of the respective body portion and an inner passage for providing fluid communication between the housing bore and the respective pocket. The mill further includes an actuator for extending the arms.