It is found that the intensity of resonant light scattering in the region of excitonic transitions in GaAs/AlGaAs quantum-well structures is modulated strongly (up to 40% under our experimental conditions) upon additional pumping of the structure by radiation with the photon energy exceeding the band gap in the barrier layers. The effect observed originates from the redistribution of the oscillator strengths of the excitonic transitions due to the formation of charged three-particle complexes (trions) made possible by the accumulation of nonequilibrium charge carriers of one particular sign (holes in our case) in the quantum wells upon above-barrier pumping.