  The current sample of high-redshift Supernova Type Ia, which combines results
from two teams, High-z Supernova Search Team and Supernova Cosmology Project,
is analyzed for the effects of weak lensing. After correcting SNe magnitudes
for cosmological distances, assuming recently published, homogeneous distance
and error estimates, we find that brighter SNe are preferentially found behind
regions (5-15 arcmin radius) which are overdense in foreground, z~0.1 galaxies.
This is consistent with the interpretation that SNe fluxes are magnified by
foreground galaxy excess, and demagnified by foreground galaxy deficit,
compared to a smooth Universe case. The difference between most magnified and
most demagnified SNe is about 0.3-0.4 mag. The effect is significant at >99%
level. Simple modeling reveals that the slope of the relation between SN
magnitude and foreground galaxy density depends on the amount and distribution
of matter along the line of sight to the sources, but does not depend on the
specifics of the galaxy biasing scheme.
