===================================================================== ==> In this proposal, more time is being requested for KERIKSSO.PROP_394 A ==> This proposal requests an upgrade from Priority 3 for KERIKSSO.PROP_394 A ===================================================================== The outer photospheres and inner regions of the circumstellar shells of AGB stars, both "O rich" and "C rich", will be explored by studies at relatively high spectral resolution of a number of molecular bands and forbidden atomic lines. The aim is to establish more reliable abundance criteria for these regions and gain further insight into their physical and chemical conditions. This will also result in more accurate estimates of mass-loss rates from CO line observations at millimetre wavelengths, as well as deeper understanding concerning the mass loss mechanisms. We were successfully granted ISO time for a major part of this project, but due to well-known circumstances (low LWS sensitivity, need for background LWS observations, etc.) severe cuts had to be made both concerning the number of spectral lines and the number of objects (the number of spectra to be observed was thus decreased by 50%). We therefore apply for time in order to restore, but also to extend the observing programme. This will lead to considerably increased scientific return; the nature of the programme makes it important to have a plurality of objects with several lines and bands for comparisons and to fill the parameter planes. Some data from the original project (PROP_394) is just now coming in, but no statement on the quality is possible yet since the data has not been processed enough (SWS spectra) or necessary software (ISAP) is not yet available.