Using the ARGUS detector at the storage ring DORIS II we have measured
tau decays into three charged mesons containing K mesons. Exploiting
the good particle identification capabilities of the detector we have
determined the following branching ratios: Br(tau(-) --> <(K(0))over
bar>pi(-)nu(tau)) = (0.25 +/- 0.10 +/- 0.05) %, Br(tau(-) --> K(0)K(
-)nu(tau)) = (0.20 +/- 0.05 +/- 0.04) %, and Br(tau(-) --> K(-)(X(0))
nu(tau)) = (1.19 +/- 0.15(-0.18)(+0.13)) %.