Search for Single Top Production at LEP via Four-Fermion Contact Interactions at

A search for single top production via Four-Fermion Contact Interactions is performed using data taken by the DELPHI detector at LEP-II. The data analysed were accumulated at centre-of-mass energies ranging from 189 to 208 GeV with an integrated luminosity of 539 pb 1 . No evidence for signal was found. Preliminary limits at 95% condence level were obtained on the characteristic energy scale, , for scalar, vector and tensor like couplings.