  We investigate the contribution of the low-energy electronic excitations
towards the Raman spectrum of bilayer graphene for the incoming photon energy
Omega >> 1eV. Starting with the four-band tight-binding model, we derive an
effective scattering amplitude that can be incorporated into the commonly used
two-band approximation. Due to the influence of the high-energy bands, this
effective scattering amplitude is different from the contact interaction
amplitude obtained within the two-band model alone. We then calculate the
spectral density of the inelastic light scattering accompanied by the
excitation of electron-hole pairs in bilayer graphene. In the absence of a
magnetic field, due to the parabolic dispersion of the low-energy bands in a
bilayer crystal, this contribution is constant and in doped structures has a
threshold at twice the Fermi energy. In an external magnetic field, the
dominant Raman-active modes are the n_{-} to n_{+} inter-Landau-level
transitions with crossed polarisation of in/out photons. We estimate the
quantum efficiency of a single n_{-} to n_{+} transition in the magnetic field
of 10T as I_{n_{-} to n_{+}}~10^{-12}.
