  The spatial averaging used for the splitting of the local scale factor on the
homogeneous background and small inhomogeneous perturbation leads to a
non-local relationship between locally and globally defined comoving curvature
perturbations. We study this relationship within a quasi-homogeneous, nearly
spatially flat domain of the Universe. It is shown that, on scales larger than
the size of the observed patch, the Fourier components of the locally defined
comoving curvature perturbation are suppressed. We have also shown that the
statistical properties of local and global comoving curvature perturbations are
coincide on a small scale. Several examples are discussed in detail.
