Acciarri, M (reprint author), Ist Nazl Fis Nucl, Sez Milano, I-20133 Milan, Italy.
A search for excited leptons, e*, mu*, tau*, nu(e)*, nu(mu)* and nu(tau)*, was performed with the L3 detector at LEP using data collected at a centre-of-mass energy of 189 GeV, corresponding to an integrated luminosity of 176 pb(-1). No evidence of their production is observed. From the searches for pair produced excited leptons, lower mass limits are set close to the kinematic limit. From the searches for singly produced excited leptons, upper limits on their couplings are derived in the mass range up to 189 GeV. (C) 2000 Published by Elsevier Science B.V. All rights reserved.