  We study the non-factorizable corrections to W-pair-mediated four-fermion
production in ee annihilation in double-pole approximation. We show how these
corrections can be combined with the known corrections to the production and
the decay of on-shell W-boson pairs, and how the full off-shell Coulomb
singularity is included. Moreover, we find that the actual form of the real
non-factorizable corrections depends on the parametrization of phase space,
more precisely, on the definition of the invariant masses of the resonant W
bosons. For the usual parametrization the full analytical results for the
non-factorizable corrections are presented. Our analytical and numerical
results for the non-factorizable corrections agree with a recent calculation,
which was found to differ from a previous one. The detailed numerical
discussion covers the invariant-mass distribution, various angular
distributions, and the lepton-energy distribution for leptonic final states.
