The processes of nonlinear interaction of two high-power pump waves with widely spaced frequencies are studied in an optical fiber. Substantially increased output power of the Stokes components, generated via stimulated Raman scattering or stimulated four-wave mixing by one of the pump waves have been obtained in the field of the other pump wave and its Stokes components. For the first time the possibility to excited new spectral lines in the spectrum of one of the pump waves with frequency shifts characteristic for the other one, is experimentally demonstrated.