A method for controlling operation of a hybrid powertrain is proposed, the hybrid powertrain comprising an internal combustion engine, an electric energy storage device, an electric machine, and an electro-mechanical transmission. The engine and the electric machine and the transmission are operative to transmit torque therebetween to generate an output. The method comprises determining optimum engine operation and an engine capability, and an operator torque request. A limit to the engine capability is determined based upon optimum engine operation, engine capability, and states of the parameters of the electrical energy storage device. Power limits are determined. The limit to the engine capability is adjusted based upon the power limits of the energy storage device. The engine operation is controlled based upon the engine capability and the adjusted limit to the engine capability.