A decrease in the longitudinal-transverse exciton splitting in a wide GaAs/AlGaAs quantum well (QW) in a homogeneous electric field has been theoretically considered. The dependences of the splitting on the applied field have been determined. The exciton reflection spectra of the wide QW have been calculated for the case where the field is oriented across the QW layer. The amplitude of exciton-related spectral oscillations is shown to decrease due to a decrease of the photo-excitonic interaction.