High-spin states and collective oblate bands in Nd139

High spin states in Nd-139 nucleus have been reinvestigated with the reaction Te-128 (O-16, 5n) at a beam energy of 90 MeV. The level scheme has been expanded with spin up to 47/2 (h) over bar. At low spin, the yrast collective structure built on the vh(11/2)(-1) multiplet shows a triaxial shape with gamma approximate to 32 degrees according to calculations of the triaxial rotor-plus-particle model. The configurations for some high spin states have been discussed from a systematic comparison with neighboring nuclei. Three collective oblate bands with gamma similar to -60 degrees at high spin were identified for the first time. A band crossing is observed around (h) over bar omega similar to 0.4 MeV in one oblate band based on the 25/2(-) level. The characteristics for these oblate bands have been discussed.