  The inclusive branching ratio for the process b -> tau nu X has been measured
using hadronic Z decays collected by the OPAL experiment at LEP in the years
1992-2000. The result is:
  BR(b -> tau nu X) = (2.78 +/- 0.18 +/- 0.51)% This measurement is consistent
with the Standard Model expectation and puts a constraint of tan(beta) /
M(H+/-) < 0.53 GeV-1 at the 95% confidence level on Type II Two Higgs Doublet
Models.
