A first full rotational analysis of high-resolution gas-phase spectra of the lowest frequency fundamental bands, nu(9) and nu(12) of formaldoxime, CH2NOH, has been completed. In addition the weak nu(7) fundamental has been analyzed at medium resolution, and the complex structure of the bands in the nu(11) and 2 nu(12) region has been revealed. It is shown that the complexity of the spectrum of the latter region is due to Coriolis interaction between the overtone 2 nu(12) and the fundamental band nu(11). The region covered in this analysis is from 8 to 30 mu m Since the molecule has C-s symmetry, in principle all the bands of A' symmetry are AB hybrids. Although the nu(4), nu(5), nu(6), and nu(8) fundamental bands described previously are predominantly A-type, the nu(7) band is found to be almost a pure B-type band, and the nu(9) band to be mainly B-type. The nu(11) and nu(12) bands are C-type bands. The main results (in cm(-1)) for the excited states are: [GRAPHICS] (C) 1996 Academic Press, Inc.