  A search for single-top production, ep --> etX, has been made with the ZEUS
detector at HERA using an integrated luminosity of 130.1 pb-1. Events from both
the leptonic and hadronic decay channels of the W boson resulting from the
decay of the top quark were sought. For the leptonic mode, the search was made
for events with isolated high-energy leptons and significant missing transverse
momentum. For the hadronic decay mode, three-jet events in which two of the
jets had an invariant mass consistent with that of the W were selected. No
evidence for top production was found. The results are used to constrain
single-top production via flavour-changing neutral current (FCNC) transitions.
The ZEUS limit excludes a substantial region in the FCNC t-u-gamma coupling not
ruled out by other experiments.
