  We study the top quark chromomagnetic factor $\kappa_t$-dependence of the
effective interaction ${\cal L}_{hgg}$ and apply the result to the case of
Higgs two gluon decay rate $\Gamma_{h\to gg}$. Perturbative standard model
provides $\kappa_t< 2$, and for the standard model value $\Gamma_{h\to
gg}(\kappa_t)$ is suppressed by 9% as compared to $\kappa_t= 2$. We further
show that in the leading order $\Gamma_{h\to gg}$ for $\kappa_t\simeq \pm 1.2$
can be very small due to complete cancelation between the top and bottom quark
fluctuations. We discuss the extension of our results to $\kappa_t>2$ and
consider potential paths to obtain experimental information for the $h\to gg$
rate.
