  We apply a reflection-based model to the best available XMM-Newton spectra of
X-ray bright UltraLuminous X-ray (ULX) sources (NGC 1313 X-1, NGC 1313 X-2, M
81 X-6, Holmberg IX X-1, NGC 5408 X-1 and Holmberg II X-1). A spectral drop is
apparent in the data of all the sources at energies 6-7 keV. The drop is
interpreted here in terms of relativistically-blurred ionized reflection from
the accretion disk. A soft-excess is also detected from these sources (as
usually found in the spectra of AGN), with emission from O K and Fe L, in the
case of NGC 5408 X-1 and Holmberg II X-1, which can be understood as features
arising from reflection of the disk. Remarkably, ionized disk reflection and
the associated powerlaw continuum provide a good description of the broad-band
spectrum, including the soft-excess. There is no requirement for thermal
emission from the inner disk in the description of the spectra. The black holes
of these systems must then be highly spinning, with a spin close to the maximum
rate of a maximal spinning black hole. The results require the action of strong
light bending in these sources. We suggest that they could be strongly
accreting black holes in which most of the energy is extracted from the flow
magnetically and released above the disc thereby avoiding the conventional
Eddington limit.
