Multitransition study and new detections of class II methanol masers

We have used the ATNF Mopra antenna and the SEST antenna to search in the d irections of several class II methanol maser sources for emission from six methanol transitions in the frequency range 85-115 GHz. The transitions wer e selected from excitation studies as potential maser candidates. Methanol emission at one or more frequencies was detected from five of the maser sou rces, as well as from Orion KL. Although the lines are weak, we find eviden ce of maser origin for three new lines in G345.01+1.79, and possibly one ne w line in G9.62+0.20. The observations, together with published maser observations at other frequ encies, are compared with methanol maser modelling for G345.01+1.79 and NGC 6334F. We find that the majority of observations in both sources are consi stent with a warm dust (175K) pumping model at hydrogen density similar to 10(6)cm(-3) and methanol column density similar to5 x 10(17) cm(-2). The su bstantial differences between the maser spectra in the two sources can be a ttributed to the geometry of the maser region.