In this paper we study germs of codimension one holomorphic, nondicritical, singular foliations in (ℂ3, 0) having no saddle-nodes in their reduction of singularities. These are called generalized surfaces. The main result says that the reduction of the singularities of a generalized surface agrees with the reduction if its separatrix set. © Astérisque 323, SMF 2009.