  The rates are measured per hadronic Z decay for gluon splitting to bb(bar)
quark pairs, g_bb, and of events containing two bb(bar) quark pairs, g_4b,
using a sample of four-jet events selected from data collected with the OPAL
detector. Events with an enhanced signal of gluon splitting to bb(bar) quarks
are selected if two of the jets are close in phase-space and contain detached
secondary vertices. For the event sample containing two bb(bar) quark pairs,
three of the four jets are required to have a significantly detached secondary
vertex. Information from the event topology is combined in a likelihood fit to
extract the values of g_bb and g_4b, namely g_bb = (3.07 +- 0.53(stat) +-
0.97(syst))x10^-3 g_4b = (0.36 +- 0.17(stat) +- 0.27(syst))x10^-3
