  A minimal extension of the standard model includes extra quarks with charges
2/3 and/or -1/3, whose left-handed and right-handed components are both SU(2)
singlets. This model predicts new interactions of flavor-changing neutral
current at the tree level, which also violate CP invariance. We study CP-odd
anomalous couplings for the gauge bosons W, W, and Z induced by the new
interactions at the one-loop level. These couplings become nonnegligible only
if both an up-type and a down-type extra quarks are incorporated. Their form
factors are estimated to be maximally of order $10^{-5}$. Such magnitudes are
larger than those predicted in the standard model, though smaller than those in
certain other models.
