  We study the neutron-proton pairing in nuclear matter as a function of
isospin asymmetry at finite temperatures and the saturation density using
realistic nuclear forces and Brueckner-renormalized single particle spectra.
Our computation of the thermodynamic quantities shows that while the difference
of the entropies of the superconducting and normal phases anomalously changes
its sign as a function of temperature for arbitrary asymmetry, the grand
canonical potential does not; the superconducting state is found to be stable
in the whole temperature-asymmetry plane. The pairing gap completely disappears
for density-asymmetries exceeding $\alpha_c= (n_n-n_p)/n \simeq 0.11$.
