This paper presents a three-phase Buck-Boost rectifier operating in continuous conduction mode (CCM). The proposed circuit provide, with a single-stage, output voltages lower or higher than input line voltage peak. The circuit has three operating modes: Boost, Buck and Buck-or-Boost. The transition between the operation modes occurs naturally, without supervisory circuits. The modulation schemes are based on a modulator with two saw tooth carriers. Sinusoidal currents with low distortion and high power factor on all operating modes were obtained. The three-phase circuit achievement is presented, along with its operational modes analysis, control and modulation strategies. In addition, the simulations results are shown, validating the theoretical analysis.