  We calculate the cross-section of the near-threshold off-shell $ZZZ$ and
$ZW^+W^-$ production at the International Linear Collider taking into account
their instability and the principal part of NLO corrections. The calculations
are performed in the framework of the model of unstable particles with smeared
mass-shell. We show that the contribution of the finite $Z/W$ and $H$ widths
(their instability) is large in the Higgs resonance range and should be taken
into account in the Higgs boson searches at future colliders.
