Apparatus for producing a yarn having a reciprocating twisting stage adapted to simultaneously twist one more slivers to produce one or more twisted strands, having one or more rollers arranged to move reciprocally along the axis of rotation of the roller(s) to impart twist to the sliver(s), and so mounted that the extent of the transverse reciprocal movement of the roller(s) can be controlled and varied to vary the twist imparted to the sliver(s) or strands.