Observations of Auger transitions to quasi-stable states of CO2+ subsequent to C 1s(-1) and O 1s(-1) ionizations of CO are presented along with the corresponding photoelectron spectra and calculations of the potential energy curves. The equilibrium distances Re, the vibrational energies h omega, and the anharmoncities xh omega for the final states a(1)Sigma(+), b(1)Pi, A(3)Sigma(+) and d(1)Sigma(+) are derived from fits to the spectra by assuming Morse potentials. A comparison of these Morse potentials with theoretical potential energy curves reveals excellent agreement in the Franck-Condon regions of the Auger transitions. The relative intensities for the observed C 1s(-1) and O 1s(-1) Auger transitions are also derived. (C) 2007 Elsevier B.V. All rights reserved.