  In most of the mass range encompassed by the limits from the direct search
and the electroweak precision tests, the Higgs boson of the standard model
preferably decays to bottom quarks. We present, in analytic form, the dominant
two-loop electroweak correction, of O(G_F^2 m_t^4), to the partial width of
this decay. It amplifies the familiar enhancement due to the O(G_F m_t^2)
one-loop correction by about +16% and thus more than compensates the screening
by about -8% through strong-interaction effects of order O(alpha_s G_F m_t^2).
