The present invention relates to a regenerated cellulose fiber, which is characterized by the combination of the following features: the fiber has in its dry condition a collapsed hollow cross-sectional structure the fiber has in its wet condition a cross-sectional structure with cavities the fiber is segmented in the longitudinal direction by dividing walls there is incorporated into the fiber an absorbent polymer, in particular carboxymethylcellulose. The fiber may be obtained by a process, wherein there is admixed a carbonate as well as an absorbent polymer, in particular carboxymethylcellulose, to a viscose dope.