  We consider the large-N limit of \mathcal{N}=6 U(N) \times U(N)
superconformal Chern-Simons (ABJM) theory with fixed level k, which is
conjectured to be dual to M-theory on AdS4\times (S^7/Z_k) background. We point
out that the so-called orbifold equivalence on the gravity side, combined with
the AdS4/CFT3 duality, predicts a hitherto unknown type of duality on the gauge
theory side. It establishes the equivalence between a class of observables,
which are not necessarily protected by supersymmetry, in strongly coupled ABJM
theories away from the planar approximation, with different values of k and N
but sharing common kN. This limit is vastly different from the planar limit,
and hence from the gauge theory point of view the duality is more difficult to
explain compared to the previously known analogous equivalence between planar
gauge theories, where one can explicitly prove the equivalence diagrammatically
using the dominance of the planar diagrams.
