The vibrational excitations of ozone, including both bending and stretching vibrations, are studied in the framework of a symmetry-adapted algebraic approach. This method is based on the isomorphism between the U(2) algebra and the one-dimensional Morse oscillator, and the introduction of point group symmetry techniques. The use of symmetry-adapted interactions, which in the harmonic limit have a clear physical interpretation, makes it possible to systematically include higher-order terms and anharmonicities. A least-squares fit to all published experimental levels (up to 10 quanta) of 16O3 and 18O3 yields rms deviations of 2.5 and 1.0 cm-1, respectively. © 1997 Academic Press.