Implications of Electroweak Precision Data on Bounds on the Higgs-Boson Mass

Carefully analyzing the dependence of the bounds on the Higgs-boson mass $\MH$ derived from the observables $\swbar^2(\LEP)$, $\swbar^2(\SLD)$, $\Gl$, $\MW$, $\GT$, $\Gh$, as well as $\Rb$ and $\Rc$, and considering the uncertainties in $\alpha(\MZ^2)$ and $\alpha_s(\MZ^2)$, we find that a stronger bound than $40\GeV\lsim\MH\lsim 1\TeV$ at the $1\sigma$ level can hardly be deduced at present, even if the experimental information on the top-quark mass $\Mt$ from direct production is taken into account.