The present invention relates to a device regulation of turbo-charging in an internal combustion engine. The turbo-charging regulation includes a first turbo unit and a second turbo unit each including appropriate turbines and compressors arranged sequentially on the exhaust and the intake sides of the engine. An engine rotational speed sensor is provided issuing a signal indicating the rotational speed of the engine. In addition, at least one pressure sensor issuing a signal indicative of an engine pressure level on the intake side of the engine is also provided. A first valve is associated with the first turbo unit and arranged to direct the engine combustion gases toward the turbine of the first turbo unit in a closed state and to direct the engine combustion gases past the turbine of the first turbo unit in an open state. A second valve is associated with the second turbo unit and arranged to direct the engine combustion gases toward the turbine of the second turbo unit in a closed state and to direct the engine combustion gases past the turbine of the second turbo unit in an open state. A central control unit is arranged to control the actuation of the first and second valves in response to signals from the rotational speed sensor and the at least one pressure sensor to provide a continuous transition between the operation of the first turbo unit and the second turbo unit.