  The TIR and FUV luminosity functions of galaxies and the related luminosity
densities rho(TIR) and rho(FUV) are known to evolve from z=0 to z~1 but with a
different rate: the galaxy populations appear brighter in the past at both
wavelengths but the evolution in TIR is larger than in FUV. It leads to an
increase of the ratio of TIR to FUV luminosity densities rho(TIR)/rho(FUV)
which can be interpreted as a global increase of the dust attenuation from z=0
to z~1. Our aim is to understand the origin of this increase. We focus on
infrared galaxies with L(TIR>10^{11} Lsun at z~0.7 observed by SPITZER/MIPS and
we measure their UV emission at 2310 A from GALEX. These Luminous InfraRed
Galaxies (LIRGs) represent the bulk of the TIR luminosity density at
intermediate redshift. Some evolution of L(TIR)/L(FUV) and therefore of dust
attenuation is found for these galaxies: LIRGs at z=0.7 span a larger range of
L(TIR)/L(FUV) ratios than at z=0 and their mean dust attenuation at FUV is
found ~0.5 mag lower than for their local counterparts. The decrease of dust
attenuation is found lower than that reported in other studies for bright
galaxies selected in UV rest-frame at z=1 and 2. From a semi-quantitative
analysis we find that the slight decrease of dust attenuation for LIRGs at
z=0.7 remains consistent with the increase of rho(TIR)/rho(FUV) with redshift.
