A method for controlling a buck-boost converter includes generating a first threshold voltage with a decreasing voltage level, generating a second threshold voltage with an increasing voltage level, and sensing an inductor current. A signal indicative of the sensed inductor current is compared to the first threshold voltage to control an on time of the high side buck switch and is compared to the second threshold voltage to control an off time of the high side boost switch. Also described is a controller including a compensator responsive to an output voltage feedback signal to generate a compensation voltage and a modulator having a buck signal path coupled to receive the compensation voltage and configured to control an on time of the high side buck switch and a boost signal path coupled to receive the compensation voltage and configured to control an off time of the high side boost switch.