Bose-Einstein correlations are studied in semileptonic (WW --> q (q) over b
ar lv) and fully hadronic (WW --> q (q) over bar q (q) over bar) W-pair dec
ays with the ALEPH detector at LEP at centre-of-mass energies of 172, 183 a
nd 189 GeV. They are compared with those made at the Z peak after correctio
n for the different flavour compositions. A Monte Carlo model of Bose-Einst
ein correlations based on the JETSET hadronization scheme was tuned to the
Z data and reproduces the correlations in the WW --> q (q) over bar lv even
ts. The same Monte Carlo reproduces the correlations in the WW --> q (q) ov
er bar q (q) over bar channel assuming independent fragmentation of the two
W's. A variant of this model with Bose-Einstein correlations between decay
products of different W's is disfavoured. (C) 2000 Published by Elsevier S
cience B.V. All rights reserved.