Pitch actuation system for a turbine engine propeller, comprising an actuator, a movable part of which is configured to be connected to blades of the propeller so as to rotate them relative to the blade pitch axes (B), comprising: a transmission screw that can rotationally and translationally move along a longitudinal axis (A), a nut, through which said transmission screw passes and which cooperates with this screw so as to translationally displace along the axis (A) with a view to modifying the pitch of the propeller blades, and means for decoupling between the rotation of the propeller and said nut, which is rotationally fixed; first blade pitch control means, which comprise at least one electric motor setting a component into rotation through a planet reduction gear with a view to modifying the position of the transmission screw; second blade feathering means configured to act on the transmission screw with a view to modifying the pitch of the blades if the first means are inactive, and in that said first planet reduction gear comprises a ring gear rigidly connected to said first component, a planet shaft rigidly connected to said first rotor and a planet carrier rigidly connected to said first housing.