  We investigate non-Gaussianity in general multiple-field inflation using the
formalism we developed in earlier papers. We use a perturbative expansion of
the non-linear equations to calculate the three-point correlator of the
curvature perturbation analytically. We derive a general expression that
involves only a time integral over background and linear perturbation
quantities. We work out this expression explicitly for the two-field slow-roll
case, and find that non-Gaussianity can be orders of magnitude larger than in
the single-field case. In particular, the bispectrum divided by the square of
the power spectrum can easily be of O(1-10), depending on the model. Our result
also shows the explicit momentum dependence of the bispectrum. This conclusion
of large non-Gaussianity is confirmed in a semi-analytic slow-roll
investigation of a simple quadratic two-field model.
