An apparatus for forming a bundle (11) of rolled bars, comprising bar conveying means (4), an inclined plane device (1) for forming a layer of bars and bar accumulation means (5), wherein the inclined plane device (1) comprises a plurality of support elements (2), arranged parallel to each another and defining a first plane inclined by an angle (a) with respect to a horizontal direction, and adapted to receive a predetermined number of bars defining the layer of bars on said first plane from said bar conveying means (4), handling means (60) for translating the inclined plane device (1) from a first maximum advancement position distal from the conveyor means (4) to a second maximum retraction position proximal to the conveyor means (4) to unload the layer of bars onto the accumulation means (5), at a speed such to prevent the bars resting on said supporting elements from being dragged.