We present 12 CO(J = 1-0) line observations of 99 galaxies obtained with the SEST 15 m, the Kitt Peak 12 m and the IRAM 30 m telescopes. The target galaxies were selected from the catalogue of isolated galaxies of Karachentseva (1973) . These data are thus representative of the CO properties of isolated late-type galaxies. All objects were observed in their central position, those with large angular sizes were mapped. These new measurements are used to estimate the molecular gas mass of the

more »

... et galaxies. The molecular gas is on average ∼18% of the atomic gas mass. Tables 1 and 2 are also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/411/381 Based on observations made with the 12-m National Radio Astronomical Observatory, Kitt Peak, Arizona, with the Swedish-ESO Submillimetre telescope SEST, La Silla, Chile, with the IRAM 30 m radiotelescope, Pico Veleta, Granada, Spain. Article published by EDP Sciences and available at