  We present an updated measurement of the time-dependent CP-violating
asymmetry in B0->K0S K0S K0S decays based on 347 million Upsilon(4S)->B Bbar
decays collected with the BABAR detector at the PEP-II asymmetric-energy B
factory at SLAC. We obtain the CP asymmetries S_f = -0.66 +/- 0.26 +/- 0.08 and
C_f = -0.14 +/- 0.22 +/- 0.05, where the first uncertainties are statistical
and the second systematic.
