  We extend Voloshin's recent analysis of charmed and beauty hyperon decays
based on SU(3) symmetry and heavy quark effective theory, by introducing a
rather moderate model-dependence, in order to obtain more predictive power,
e.g. the values of lifetimes of the (\Lambda_{b},\Xi_{b}) hyperon triplet and
the lifetime of \Omega_{b}. In this way we obtain an improvement of the ratio
\tau(\Lambda_{b})/\tau(B_{d}^{0}) \sim 0.9 and the hierarchy of lifetimes
\tau(\Lambda_{b}) \simeq \tau(\Xi_{b}^{0}) < \tau(\Xi_{b}^{-}) <
\tau(\Omega_{b}) with lifetimes of \Xi_{b}^{-} and \Omega_{b} exceeding the
lifetime of \Lambda_{b} by 22% and 35%, respectively.
