  Based on a sample of four million events collected by ALEPH from 1991 to
1995, a measurement of the forward-backward asymmetry in Z -> b-barb decays
using inclusive final states is presented. High-performance tagging of b-barb
events in a wide angular range is achieved using neural network techniques. An
optimal hemisphere charge estimator is built by merging primary and secondary
vertex information, leading kaon identification and jet charge in a neural
network. The average charge asymmetry, the flavour tagging efficiencies and
mean b-hemisphere charges are measured from data and used to extract the pole b
asymmetry in the Standard Model A^{0,b}_{FB} = 0.1009 +- 0.0027 (stat) +-
0.0015 (syst), corresponding to a value of the effective weak mixing angle of
sin^2(theta_W^{eff}) = 0.23193 +- 0.00056.
