A rotating leno forming device includes a leno disk (3) that has leno thread guides (5) therein and that itself forms a part of the rotor (2) of an electromagnetic drive arrangement. In order to achieve a very compact bearing support arrangement, shield the moving parts against external contamination, and provide for the detection of the rotational position of the leno disk, the leno device further includes a roller or ball bearing (6) of which the outer bearing race (6A) is rigidly connected to the leno disk (3), and of which the inner bearing race (6B) is rigidly connected to a centering holder (9) that is rigidly connected to a housing (8) of the leno device. Permanent magnets (7) are arranged around the circumference of the rotor (2) and cooperate with an electromagnetic stator (11) secured in the housing (8). A position sensor system (10) includes at least one signal emitter (13) mounted on the rotor (2) and a plurality of signal receivers or sensors (14) mounted on the housing (8).