  We perform a statistical analysis of AGN host characteristics and nuclear
activity for AGNs in pairs and without companions. Our study concerns a sample
of AGNs derived from the SDSS-DR4 data by Kauffmann et al (2003) and pair
galaxies obtained from the same data set by Alonso et al. (2006). An eye-ball
classification of images of 1607 close pairs ($r_p<25$ kpc $h^{-1}$, $\Delta
V<350$ km $s^{-1}$) according to the evidence of interaction through distorted
morphologies and tidal features provides us with a more confident assessment of
galaxy interactions from this sample. We notice that, at a given luminosity or
stellar mass content, the fraction of AGNs is larger for pair galaxies
exhibiting evidence for strong interaction and tidal features which also show
sings of strong star formation activity. Nevertheless, this process accounts
only for a $\sim 10%$ increase of the fraction of AGNs. As in previous works,
we find AGN hosts to be redder and with a larger concentration morphological
index than non-AGN galaxies. This effect does not depend whether AGN hosts are
in pairs or in isolation. The OIII luminosity of AGNs with strong interaction
features is found to be significantly larger than that of other AGNs, either in
pairs or in isolation. Estimations of the accretion rate, $L[OIII]/M_{BH}$,
show that AGNs in merging pairs are actively feeding their black holes,
regardless of their stellar masses. We also find that the luminosity of the
companion galaxy seems to be a key parameter in the determination of the black
hole activity. At a given host luminosity, both the OIII luminosity and the
$L[OIII]/M_{BH}$ are significantly larger in AGNs with a bright companion ($M_r
< -20$) than otherwise.
