  We study the holographic duality between the M x M matrix extension of
Vasiliev higher spin theories on AdS3 and the large N limit of SU(N+M)/SU(N) x
U(1) type cosets. We present a simplified proof for the agreement of the
spectra and clarify the relation between this duality and the version in which
the cosets are replaced by Kazama-Suzuki models of Grassmannian type.
