A method for controlling operating modes of a hybrid powertrain mechanism including a first epicyclic train having first and second sun gears and a planetary gear couplable to these sun gears; a second epicyclic train having third and fourth sun gears and a planetary gear couplable to these sun gears; a first electric machine having one end coupled to the second sun gear; a second electric machine having one end coupled to the fourth sun gear; a first clutch having one end coupled to another end of the first electric machine; a first brake having one end coupled to another end of the first clutch and another end coupled to the third sun gear; and an engine coupled to the first sun gear. Various driving modes are provided by changing the states of the first clutch and the first brake and the operating modes of the first and second electric machines.