  We present the result of a direct search for the decay K_S -> e+e-, obtained
with a sample of e+e- -> phi -> K_S K_L events produced at DAFNE, the Frascati
phi-factory, for an integrated luminosity of 1.9 fb^-1. The search has been
performed using a pure K_S beam tagged by the simultaneous detection of a K_L
interaction in the calorimeter. Background rejection has been optimized by
using both kinematic and particle identification cuts. We find BR(K_S -> e+e-)
< 9x10^-9 at 90% CL, which improves by an order of magnitude on the previous
best limit.
