Studying the relative motion of test bodies in general relativity attracts a considerable interest. Various sides of this problem have been studied in a series of papers. In [i], the exponential mapping in the neighborhood of reference trajectory was used in order to obtain and study the exact solutions for the relative motion of geodesic lines, as well as their approximations up to and including the third order in the deviation vector and its derivatives. In [2], the geometrical aspects of the problem were studied, the exact equation of the relative motion of test bodies in an external field was written, and for all essential geometric quantities, in particular, for the connection coefficients up to the fourth order, expansions in powers of normal coordinates were obtained. In the series of papers [3], the asymptotic methods of the theory of nonlinear oscillations were applied to study nonlinear effects in the relative motion of test bodies.