96-13E

The class of two-particle relativistic models which are described by the time-asymmetric Fokker-type integral of general form is considered. The manifestly covariant description of such models is constructed in the framework of the canonical formalism with constraints. By means of certain gauge fixing, the time-asymmetric models are reduced to the Bakamjian-Thomas model supplemented by a space-time interpretation. The corresponding two-body problem is reduced to quadratures.