  We examine very general four-point interactions arising from new physics and
contributing to the Higgs production process e+e- -> HZ. We write all possible
forms for these interactions consistent with Lorentz invariance. We allow the
possibility of CP violation. Contributions to the process from anomalous ZZH
and gamma ZH interactions studied earlier arise as a special case of our
four-point amplitude. We consider the decay of Z into a charged lepton pair and
obtain expressions for angular distributions of charged leptons arising from
the interference of the four-point contribution with the standard-model
contribution. We take into account possible longitudinal or transverse beam
polarization likely to be available at a linear collider. We examine several
correlations which can be used to study the various form factors present in the
e+e-HZ contact interactions. We also obtain the sensitivity of these
correlations in constraining the new-physics interactions at a linear collider
operating at a centre-of-mass energy of 500 GeV with longitudinal or transverse
polarization.
