Author Institution: Groupe de Spectrom\'etrie Mol\'eculaire et Atmosph\'erique, UMR CNRS 6089 Universit\'e de Reims - Moulin de la Housse - BP 1039After the previous systematic analysis of 16O3​1,18O3​2,16O18O16O3,4 in medium infrared, we present here the results of the analysis of new 18O16O18O observed bands. The spectra have been recorded with the FTS of Reims5,6, with a resolution of 0.006cm−1, and products pathlength × pressure up to 32m×3 Torr. The data reduction to derive line positions uses a new multifit program7. The analysis of spectra is performed using the same formalism as in references [1-4], using standard Watson's Hamiltonian for diagonal blocks and Coriolis and Fermi resonances for off diagonal blocks. 8 polyads have been analysed, among them 7 being analysed for the first time. They correspond to 10 observed bands (underlined) in interaction with ``dark'' bands. (ν1​,ν3​);(ν2​+ν3​,ν1​+ν2​);(ν2​+2ν3​,ν1​+ν2​+ν3​,2ν1​+ν2​);(3ν3​,ν1​+2ν3​,2ν1​+ν3​);(ν2​+3ν3​);(ν1​+3ν3​,4ν3​);(ν1​+ν2​+3ν3​,ν2​+4ν3​)and(5ν3​)​ We give here the range of J and Ka​ for observed transitions, statistics for energy levels, spectroscopic parameters and resonance coupling parameters. Acknowledgments: Authors thank S.A Tashkun for use of GIP programs, X. Thomas and P. Von der Heyden for recording spectra, L. R\'{e}galia and J. J. Plateaux for the use of multifit program. 1. S. M. Mikhailenko, A. Barbe, VI. G. Tyuterev and A. Chichery, Atmos. Oceanic Opt., 12, 9 (1999) 2. A. Chichery, A. Barbe, VI. G. Tyuterev, J. Molecular Spectrosc., 206, 1 - 26 (2001) 3. A. Chichery, A. Brabe, VI. G. Tyuterev, S.A. Tashkun, J. Molecular Spectrosc., 205, 347-349 (2001) 4. M. R. De Backer Barilly, A. Barbe, VI. G. Tyuterev, A. Chichery, Mol. Phys., accepted (2002). 5. J.J. Plateaux, A. Barbe, and A. Delahaigue, Spectrochim. Acta, A 51, 1153-1196 (1995). 6. L. R\'{e}galia, Thesis Universit\'{e} de Reims, (France) (1996). 7. J.J. Plateaux, L. R\'{e}galia, C. Boussin and A. Barbe, J.Q.S.R.T., 68, 507-520 (2001)