  The odd-parity spin-triplet Cooper pairing states show a six-fold degeneracy
for a quasi-two-dimensional electron system. In this article we show how
spin-orbit coupling can lift this degeneracy for Sr_2RuO_4 taking the band
structure based on the three relevant t_{2g}-orbitals of the Ru-ions into
account. The stabilized state depends on the relative strength of the pairing
interaction. We show that under reasonable assumptions the chiral pairing state
d(k) = z(k_x +/- i k_y) is favored against the others.
