We demonstrate a near-infrared electro-optic modulator with a bandwidth of 3 GHz and a V(pi)L figure of merit of 0.8 V-cm using a push-pull configuration. This is the highest operating speed achieved in a silicon-polymer hybrid system to date by several orders of magnitude. The modulator was fabricated from a silicon strip-loaded slot waveguide and clad in a nonlinear polymer. In this geometry, the electrodes form parts of the waveguide, and the modulator driving voltage drops across a 200 nm slot.