  The algebraic method of singular reduction is applied for non regular group
action on manifolds which provides singular symplectic spaces. The problem of
deformation quantization of the singular surfaces is the focus. For some
examples of singular Poisson spaces the deformation quantization is explicitly
constructed. In is shown that for the flat phase space with the classical
moment map and the orthogonal group action the deformation quantization
converges for the entire arguments of exponential type.
