  Using a sample of 4.7/fb integrated luminosity accumulated with the CLEO-II
detector at the Cornell Electron Storage Ring (CESR), we have measured the
branching fractions of the tau lepton into $K^- h^+ \pi^- \nu_\tau$ and $K^-
K^+ \pi^- \nu_\tau$ relative to $h^- h^+ h^- \nu_\tau; K^- h^+ \pi^-
\pi^0\nu_\tau$ and $K^- K^+ \pi^- \pi^0\nu_\tau$ relative to $h^- h^+ h^- \pi^0
\nu_\tau$. The relative branching fractions are: (5.16+-0.20+-0.50)*$10^{-2}$,
(1.52+-0.14+-0.29)*$10^{-2}$, (2.54+-0.44+-0.39)*$10^{-2}$ and $<0.0154$ at 95%
C.L., respectively. Coupled with additional experimental information, we use
our results to extract information on the structure of three-prong tau decays
to charged kaons.
