  If the charged Higgs boson H+ exists with mh < mt + mb, the conventional
expectation is that it will decay dominantly into c s-bar and tau+ nu-tau.
However, the three-body decay mode H+ --> W+ b b-bar is also present and we
show that it becomes very important in the low tan(beta) region for mh >~ 140
GeV. We explore its phenomenological implications for the charged-Higgs-boson
search in top-quark decay.
