  We give a brief account of the recently proposed N=3 superfield formulation
of the N=6, 3D superconformal theory of Aharony et al (ABJM) describing a
low-energy limit of the system of multiple M2-branes on the AdS_4 x S^7/Z_k
background. This formulation is given in harmonic N=3 superspace and reveals a
number of surprising new features. In particular, the sextic scalar potential
of ABJM arises at the on-shell component level as the result of eliminating
appropriate auxiliary fields, while there is no any explicit superpotential at
the off-shell superfield level.
