  We examine extended bound states in the dilute limit of the extended Hubbard
model with next-nearest-neighbour (nnn) hopping and nnn interactions on the two
dimensional square lattice. By the exact solution of a two-body problem we show
that d-wave pairing is strongly favored by the nnn hopping. We determine the
binding energies, mobilities and dispersion curves across Brillouin zone (B.z.)
for bound states of various symmetries. The numerical analysis shows that the
deep bound states can exist in the whole B.z. and we have also found s*-d
mixing of the bound states.
