In this paper an active brake control for reducing the rollover risk of heavy vehicles is proposed. The brake system is activated only when the vehicle comes close to rolling over. A parameter dependent gain is applied to the normalised lateral load transfer, since the brake is activated when it has reached the critical value. The control design is based on the Linear Parameter Varying (LPV) model of yaw-roll dynamics of heavy vehicles. In the control design both the performance demands and the model uncertainties are taken into consideration. In order to enhance the performance of the active brake, this mechanism is extended with a prediction procedure, in which the critical values are predicted in advance using a short time interval. The control mechanism is demonstrated in vehicle manoeuvres.