A modular conveyor belt (10) comprises a plurality of first rows of one or more belt modules (20) and a plurality of second rows of one or more belt modules (40). Each of the first rows comprises a first drive surface (26) for receiving a force-transmitting surface of a first series of force-transmitting surfaces of a drive sprocket, the first drive surfaces (26) of the first rows being arranged along a first line in a direction of belt travel (T). Each of the second rows comprises a second drive surface (48) for receiving a force-transmitting surface of a second series of force-transmitting surfaces of the drive sprocket, the second drive surfaces (48) of the second rows being arranged along a second line in the direction of belt travel (T). The first line and the second line are offset with respect to each other. Each belt module (20) of the first rows comprises a first middle section (22) between two link sections (21), which has a first flat top surface and is arranged adjacent to a second middle section (42) between two link sections (41) of an adjacent belt module (40) of one of the adjacent second rows having a second flat top surface. The first flat top surface and the second flat top surface have a different width in the direction of belt travel (T) at least in adjacent zones and the first and second middle sections (22, 42) are devoid of linking means.