  In a previous work, a marginal deformation of 2d coset type model with N=3
superconformal symmetry was studied, and it was interpreted as a change of
boundary conditions for bulk fields in the dual higher spin theory. The
deformation breaks generic higher spin gauge symmetry, and the generated mass
of a spin 2 field was computed. The deformation might be related to the
introduction of finite string tension in a superstring theory. In this paper,
we extend the analysis and compute the masses of generic higher spin fields at
the leading order of 1/c (c is the CFT central charge) but at the full order of
the deformation parameter. We find that the masses are not generated for
so(3)_R singlet higher spin fields at this order and the spectrum is the
Regge-like one for so(3)_R triplet higher spin-charged fields.
