  We study the formation of the spectra in advection dominated accretion flows
(ADAFs) around Kerr black holes. We use a Monte Carlo approach and fully
general relativistic treatment to follow the paths of individual photons and
model their scattering with mildly relativistic, thermal electrons of the two
temperature plasma present in the flow. We are mostly interested in the
dependence of the spectra on the black hole angular momentum, and we find that
the influence of the black hole rotation rate on the flow structure has an
impact on the resulting spectra. The flows around the fast rotating holes
produce relatively harder spectra. This property of the models should be taken
into account when modeling the individual sources and the population of
inefficiently accreting black holes in the Universe.
