SEARCH FOR INDIRECT NEW PHYSICS EFFECTS IN E(-)-]W+W- AT LINEAR COLLIDERS WITH POLARIZED BEAMS()E()

We discuss the potential of a 0.5 TeV linear collider to explore manif estations of extended (or alternative) electroweak models of current i nterest, through measurements of the reaction e(+)e(-) --> W+W- with b oth initial and final states polarization. Specifically, we consider t he possibility to put stringent constraints on lepton mixing (or exten ded lepton couplings) and Z - Z' mixing, showing in particular the use fulness of polarization in order to disentangle these effects.