  We present results of an infrared-to-X-ray study of 76 bright soft X-ray
selected Seyfert galaxies discovered in the ROSAT All-Sky Survey. These objects
are characterized by steep X-ray spectra in the 0.2-2.0 keV bandpass with power
law energy spectral indices in the range of 1.3 to 8 and a lack of internal
absorption by neutral hydrogen. Our sample selection based on hardness ratio
yields a mean X-ray slope of alpha-X = 2.1, steeper than in any other known AGN
population. At optical wavelengths, the soft AGN have significantly bluer
spectra than a comparison sample of AGN with a canonical, harder X-ray
spectrum, whereas the slope between 5500 Angstrom and 1 keV is the same. This
is consistent with a more pronounced Big Blue Bump emission component in the
soft X-ray selected AGN. The blueness of the optical spectra increases with the
softness of the X-ray spectra and with the luminosity, saturating at an
approximate F_nu proportional to nu^+0.3 spectrum. Such properties are expected
if most of the Big Blue Bump emission originates in a (comptonized) accretion
disk and accretion rate to mass ratio is higher than in AGN with a hard X-ray
spectrum.
