Effects of an anomalous ZWW vertex on Z decays.

We consider the effects of an anomalous quadrupole moment of the {ital W} on the {ital Z}{sup 0} branching ratios and asymmetries at the CERN {ital e}{sup +}{ital e}{sup {minus}} collider LEP. Stringent experimental constraints from the {rho} parameter are evaded if {lambda}{sub {gamma}}={lambda}{sub {ital Z}}{identical to}{lambda}. We therefore choose a scheme based on a custodial global SU(2){sub weak} symmetry, implemented with the {ital W}-dominance mechanism such that {rho}=1 is enforced. With the expected accuracy at LEP, we find that, for the scale of new physics {Lambda}=1 TeV, a limit {vert bar}{lambda}{vert bar}{le}0.34 can be obtained for this coupling. This is as good a limit as can be set at LEP 200.