The authors report the observation of strongly polarization-sensitive resonances in the electroreflectance (ER) spectra of multilayered semiconductor structures. The measurements were done on vertical-cavity surface-emitting laser structures grown on GaAs(001) substrates. The ER spectral features undergo a 180° phase shift as the polarization vector E of the probe beam is rotated by 90° from E∥[1 1̄ 0] to E∥[110] in the (001) plane. Through experiments and simulations, these resonances are shown to arise due to the linear electro-optic effect (LEOE). The influence of LEOE at energies below the band gap becomes prominent mainly because of optical-interference induced enhancement of the Seraphin coefficients in a multilayered structure. Implications for the analysis of ER spectral lineshapes of multilayered semiconductor structures are highlighted. © 2008 The American Physical Society.