A power-split transmission having several ranges of transmission ratios with continuously variable speed reductions. A drive shaft is connected to two shafts of a variable speed drive unit via a distributor gear whose shafts are in turn connected with the input shafts of a parallel gearbox via respective clutches. Two ranges of ratios only differ from each other through the reduction of the input shaft of the parallel gearbox and their output shafts. An additional embodiment includes a variable speed drive unit, a first planetary drive that is connected with a drive shaft, an input shaft of the variable speed drive unit and a connecting shaft, as well as a second planetary drive that is connected with the connecting shaft of the output shaft of the variable speed drive unit, and an output shaft and an electric motor that is nonrotatably connected with the connecting shaft.