The relationship between the perturbation theory in light-front
coordinates and \linebreak Lorentz-covariant perturbation theory is
investigated. A method for finding the difference between
separate terms of the corresponding series without their
explicit evaluation is proposed. A procedure of constructing
additional counter-terms to the canonical Hamiltonian that
compensate this difference at any finite order is proposed. For
the Yukawa model, the light-front Hamiltonian with all of these
counter-terms is obtained in a closed form. Possible application
of this approach to gauge theories is discussed.