  It is pointed out that the retardation terms given in the original
Fermi-Breit potential vanish in the center of mass frame. The retarded
one-gluon exchange potential is rederived in this paper from the
three-dimensional one-gluon exchange kernel which appears in the exact
three-dimensional relativistic equation for quark-antiquark bound states. The
retardation part of the potential given in the approximation of order $p^2/m^2$
is shown to be different from those derived in the previous literature. This
part is off-shell and does no longer vanish in the center of mass frame.
