We show tuning of the resonance wavelength of silicon-on-insulator microring resonators with liquid crystal cladding. The electro-optic effect of the liquid crystal causes a decrease in effective refractive index for the TE-polarized light in the waveguides. Tuning of the liquid crystal birefringence affects primarily the longitudinal component of the electric field. We achieve a tuning range of 0.6 nm. Through simulation and experiment we perform a thorough study of this phenomenon.