A thrust reverser for a nacelle of an aircraft turbojet engine comprising at least: - a thrust reverser cowl movable in translation along a direction substantially parallel to a longitudinal axis of the nacelle, between a direct jet position and a reversed jet position, - an outlet nozzle of a variable section which is arranged in the downstream extension of said cowl and which is movable between at least one reduced ejection section position and one increased ejection section position, - an actuator which comprises a body mounted on the fixed structure of the thrust reverser and an actuating rod, said rod being adapted to drive in displacement the variable nozzle and the movable cowl, - a first device for locking the cowl in its direct jet position on the fixed structure of the thrust reverser, which comprises a locking hook pivotally mounted about a transverse axis, between a closed locking position of the cowl in which the hook cooperates with a locking finger secured to the thrust reverser cowl, and an open locking position of the cowl in which the hook releases said finger, - a second device for locking the nozzle on the thrust reverser cowl, adapted to occupy alternately a locking position of the nozzle on the cowl and an unlocking position of the nozzle, - characterized in that it includes a reset lever which is designed to be pivotally driven by the finger, about a transverse axis, from a rest position to a reset position, the lever being pivotally linked on the hook at least in the direction of closure of the hook, so that the pivotal driving of the lever by the finger toward its rest position drives the hook toward its locking position, - an actuating arm movably mounted on the cowl between a locking position of the nozzle in which said arm actuates the second locking device to lock the nozzle on the thrust reverser cowl, and an unlocking position of the nozzle in which said arm unlocks the nozzle, said arm being driven in its locking position by the locking hook, during the pivoting of the hook toward its unlocking position. - a thrust reverser cowl movable in translation along a direction substantially parallel to a longitudinal axis of the nacelle, between a direct jet position and a reversed jet position, - an outlet nozzle of a variable section which is arranged in the downstream extension of said cowl and which is movable between at least one reduced ejection section position and one increased ejection section position, - an actuator which comprises a body mounted on the fixed structure of the thrust reverser and an actuating rod, said rod being adapted to drive in displacement the variable nozzle and the movable cowl, - a first device for locking the cowl in its direct jet position on the fixed structure of the thrust reverser, which comprises a locking hook pivotally mounted about a transverse axis, between a closed locking position of the cowl in which the hook cooperates with a locking finger secured to the thrust reverser cowl, and an open locking position of the cowl in which the hook releases said finger, - a second device for locking the nozzle on the thrust reverser cowl, adapted to occupy alternately a locking position of the nozzle on the cowl and an unlocking position of the nozzle, - characterized in that it includes a reset lever which is designed to be pivotally driven by the finger, about a transverse axis, from a rest position to a reset position, the lever being pivotally linked on the hook at least in the direction of closure of the hook, so that the pivotal driving of the lever by the finger toward its rest position drives the hook toward its locking position, - an actuating arm movably mounted on the cowl between a locking position of the nozzle in which said arm actuates the second locking device to lock the nozzle on the thrust reverser cowl, and an unlocking position of the nozzle in which said arm unlocks the nozzle, said arm being driven in its locking position by the locking hook, during the pivoting of the hook toward its unlocking position.