The influence of charge asymmetry on the dynamic characteristics of a rotary motion of a shielded body is investigated; the body acted upon by gravitational and Lorentz forces moves in the geomagnetic field in a circular equatorial orbit. The sufficient and necessary conditions are formulated for the stability of relative equilibrium positions; the regions of admissible parameter values are constructed and the influence of charge asymmetry on the sizes of these regions and the oscillation frequencies are defined.