The ESO/VLT 3rd year Type Ia supernova data set from the Supernova
  Legacy Survey
  We present 139 spectra of 124 Type Ia supernovae (SNeIa) that were observed
at the ESO/VLT during the first three years of the Canada-France-Hawai
Telescope (CFHT) Supernova Legacy Survey (SNLS). This homogeneous data set is
used to test for redshift evolution of SNeIa spectra, and will be used in the
SNLS 3rd year cosmological analyses.
  Spectra have been reduced and extracted with a dedicated pipeline that uses
photometric information from deep CFHT Legacy Survey (CFHT-LS) reference images
to trace, at sub-pixel accuracy, the position of the supernova on the
spectrogram as a function of wavelength. It also separates the supernova and
its host light in 60% of cases. The identification of the supernova candidates
is performed using a spectrophotometric SNIa model.
  A total of 124 SNeIa, roughly 50% of the overall SNLS spectroscopic sample,
have been identified using the ESO/VLT during the first three years of the
survey. Their redshifts range from z=0.149 to z=1.031. The average redshift of
the sample is z=0.63+/-0.02. This constitutes the largest SNIa spectral set to
date in this redshift range. The spectra are presented along with their
best-fit spectral SNIa model and a host model where relevant. In the latter
case, a host subtracted spectrum is also presented. We produce average spectra
for pre-maximum, maximum and post-maximum epochs for both z<0.5 and z>=0.5
SNeIa. We find that z<0.5 spectra have deeper intermediate mass element
absorptions than z>= 0.5 spectra. The differences with redshift are consistent
with the selection of brighter and bluer supernovae at higher redshift.
