The pair production of Z bosons is studied using the data collected by the
L3 detector at LEP in 1998 in e(+)e(-) collisions at a centre-of-mass energ
y of 189 GeV. All the visible final states are considered and the cross sec
tion of this process is measured to be 0.74(-0.14)(+0.15)(stat.) +/- 0.04(s
yst)pb. Final states containing b quarks are enhanced by a dedicated select
ion and their production cross section is found to be 0.18(-0.07)(+0.09)(st
at) +/- 0.02(syst) pb. Both results are in agreement with the Standard Mode
l predictions. Limits on anomalous couplings between neutral gauge bosons a
re derived from these measurements. (C) 1999 Published by Elsevier Science
B.V. All rights reserved.