We find the symmetry algebras of cosets which are generalizations of the minimalmodel cosets, of the specific form SU (N ) k ×SU (N ). We study this coset in its free field limit, with k, → ∞, where it reduces to a theory of free bosons. We show that, in this limit and at large N , the algebra W e ∞ [1] emerges as a sub-algebra of the coset algebra. The full coset algebra is a larger algebra than conventional W-algebras, with the number of generators rising exponentially with the spin, characteristic of a stringy growth of states. We compare the coset algebra to the symmetry algebra of the large N symmetric product orbifold CFT, which is known to have a stringy symmetry algebra labelled the 'higher spin square'. We propose that the higher spin square is a sub-algebra of the symmetry algebra of our stringy coset.