The purpose of this communication is the de nition and investigation of a new inverse operation in the class of preradicals PR of the category R-Mod of left R-modules. In [1] and [2] two inverse operations, the left quotient with respect to join and the left coquotient with respect to meet, are de ned and studied. These operations exist for any pair of preradicals of PR. In [3] another inverse operation is introduced and investigated, namely the left quotient with respect to meet which, in contrast to the preceding cases, is partial. In the present lecture in a similar manner as in [3], a new partial inverse operation is de ned. We will show the criteria of existence of this operation, its main properties, the relations with the lattice operations of PR and some particular cases.