  A generalization of the operator product expansion for Euclidean correlators
of gauge invariant QCD currents is presented. Each contribution to the modified
expansion, which is based on a delocalized multipole expansion of a
perturbatively determined coefficient function, sums up an infinite series of
local operators. On a more formal level the delocalized operator expansion
corresponds to an optimal choice of basis sets in the dual spaces which are
associated with the interplay of perturbative and nonperturbative N-point
correlations in a distorted vacuum. A consequence of the delocalized expansion
is the running of condensates with the external momentum. Phenomenological
evidence is gathered that the gluon condensate, often being the leading
nonperturbative parameter in the OPE, is indeed a function of resolution.
Within a model calculation of the nonperturbative corrections to the ground
state energy of a heavy quarkonium system it is shown exemplarily that the
convergence properties are better than those of the OPE. Potential applications
of the delocalized operator expansion in view of estimates of the violation of
local quark-hadron duality are discussed.
