The asymmetric Anderson model with an infinite conduction electron band-width is studied at absolute zero within a particle-particle t-matrix (ladder) approximation. The self-energy of the d-electron is found to increase as #x0394;/πlog (U/π#x0394;) for strong Coulomb repulsion U and finite level-width #x0394;. For small U/π#x0394; the approximation reproduces the correct result of the perturbation theory. Spin and charge susceptibilities are calculated as a function of U. The case of attractive U is also examined.