Turbomachine compressor comprising variable-pitch vanes comprising an aerofoil section connected by a mounting plate (17) of circular outline to a pivot (18) guided in rotation in an orifice in a casing (14), the mounting plate of the vane comprising at least one notch (60) for bleeding air from the compressor stream, this notch being intended to communicate with a hole (62) in the casing in order to remove the air bled off when the vanes are in a first position, and to be closed off by this casing when the vanes are in a second position, so that the flow rate of bled air depends on the pitch angle of the vanes.