A circular knitting machine for manufacturing open-work knitted fabric, comprising: - a needle-holding cylinder having a plurality of longitudinal grooves arranged around a central axis (X-X) of the needle-holding cylinder; - a plurality of needles, each being housed in a respective longitudinal groove; - at least one yarn feed operatively associated to the needles; - a crown arranged around the needle-holding cylinder and having a plurality of radial grooves; - at least one guiding ring operatively associated to the crown, wherein the crown is rotatable with respect to the guiding ring and around the central axis (X-X); - a plurality of knockover sinkers, each housed in one of the radial grooves and radially movable in the respective radial groove, each knockover sinker having a pin configured for cooperating with the needles and a butt engaged with a first guide obtained in the guiding ring and developing around the central axis (X-X); wherein the first guide is configured for moving the knockover sinker radially along the respective radial groove when the crown rotates with respect to the guiding ring and around the central axis (X-X); - at least one shaped sinker (8, 9) placed beside each of the knockover sinkers, wherein the shaped sinker (8, 9) is movable with respect to the respective knockover sinker, wherein the shaped sinker (8, 9) has a protrusion placed above the respective knockover sinker and laterally offset with respect to said knockover sinker, wherein the protrusion is configured for loading and extending the inter-stitch and place it on an adjacent needle of said plurality of needles and make an open work, wherein the shaped sinker (8, 9) has a butt that is engaged with a second guide obtained in the guiding ring and developing around the central axis (X-X), wherein the second guide defines a plurality of trajectories for the shaped sinker (8, 9), wherein the second guide is configured for moving the shaped sinker (8, 9) radially when the crown rotates with respect to the guiding ring and around the central axis (X-X); said machine being characterized in that it further comprises: - at least one selector operatively coupled with said at least one shaped sinker (8, 9), wherein the selector is oscillating, in a radial plane with respect to the crown, between a rest position and an operating position, wherein in the operating position the selector acts directly or indirectly upon said at least one shaped sinker (8, 9) so as to deviate the butt of the shaped sinker (8, 9) along a trajectory of the second guide; - at least one selecting actuator laterally facing the crown, fixed with respect to the guiding ring, that can be engaged under control with the selectors and is configured for causing the at least one selector to switch from the rest position to the operating position. - a needle-holding cylinder having a plurality of longitudinal grooves arranged around a central axis (X-X) of the needle-holding cylinder; - a plurality of needles, each being housed in a respective longitudinal groove; - at least one yarn feed operatively associated to the needles; - a crown arranged around the needle-holding cylinder and having a plurality of radial grooves; - at least one guiding ring operatively associated to the crown, wherein the crown is rotatable with respect to the guiding ring and around the central axis (X-X); - a plurality of knockover sinkers, each housed in one of the radial grooves and radially movable in the respective radial groove, each knockover sinker having a pin configured for cooperating with the needles and a butt engaged with a first guide obtained in the guiding ring and developing around the central axis (X-X); wherein the first guide is configured for moving the knockover sinker radially along the respective radial groove when the crown rotates with respect to the guiding ring and around the central axis (X-X); - at least one shaped sinker (8, 9) placed beside each of the knockover sinkers, wherein the shaped sinker (8, 9) is movable with respect to the respective knockover sinker, wherein the shaped sinker (8, 9) has a protrusion placed above the respective knockover sinker and laterally offset with respect to said knockover sinker, wherein the protrusion is configured for loading and extending the inter-stitch and place it on an adjacent needle of said plurality of needles and make an open work, wherein the shaped sinker (8, 9) has a butt that is engaged with a second guide obtained in the guiding ring and developing around the central axis (X-X), wherein the second guide defines a plurality of trajectories for the shaped sinker (8, 9), wherein the second guide is configured for moving the shaped sinker (8, 9) radially when the crown rotates with respect to the guiding ring and around the central axis (X-X); said machine being characterized in that it further comprises: - at least one selector operatively coupled with said at least one shaped sinker (8, 9), wherein the selector is oscillating, in a radial plane with respect to the crown, between a rest position and an operating position, wherein in the operating position the selector acts directly or indirectly upon said at least one shaped sinker (8, 9) so as to deviate the butt of the shaped sinker (8, 9) along a trajectory of the second guide; - at least one selecting actuator laterally facing the crown, fixed with respect to the guiding ring, that can be engaged under control with the selectors and is configured for causing the at least one selector to switch from the rest position to the operating position.