A nonlinear Fabry-Perot resonator (FPR) with a homeotropically aligned nematic liquid crystal (NLC) is experimentally investigated. Specific nonlinear optical features of this kind of FPR are connected with the threshold character of light beam orientational interaction with the NLC. Optical Freedericksz transition, bistability, power limiting and stabilization are realized for small radiation intensities. Transverse pattern formation and rich dynamics are observed.