The stator includes a casing and at least one stage of variable-pitch stator vanes. The vanes are moved by an actuator ring outside the casing and are carried thereby. The ring is connected by links to the vanes in order to actuate them simultaneously. The casing includes a stationary coaxial rail projecting from the outside surface of the casing and at least three circumferentially spaced-apart groups of wheels are constrained to move along the rail. Each group of wheels is coupled to the ring by a radial guidance arrangement. Each group of wheels includes at least two wheels engaged with the rail, and each wheel being mounted to rotate on a radially-oriented pin, said pin being mounted directly on said ring.