  We discuss possible pairing symmetries in the hexagonal pnictide
superconductor SrPtAs. The local lack of inversion symmetry of the two distinct
conducting layers in the unit cell results in a special spin-orbit coupling
with a staggered structure. We classify the pairing symmetry by the global
crystal point group D_3d, and suggest some candidates for the stable state
using a tight-binding model with an in-plane, density-density type pairing
interaction. We may have some unconventional states like s+f-wave and a mixture
of chiral d-wave and chiral p-wave. The spin orbit coupling is larger than the
interlayer hopping, and the mixing between spin-singlet and triplet states can
be seen in spite of the fact that the system has a global inversion center.
