Sanofi-Aventis’ ticker is SNY. (Sony is SNE.) AVE is the ticker for Aventis, which continues to trade as a “stub” company, but has no independent significance.
Sanofi acquired Aventis via a tender offer. Almost all of the Aventis shareholders tendered, but there are a few who held out. As long as the NYSE and other international markets continue to list AVE shares, these holdouts can continue trading.
At some point, SNY will commence a routine legal action to forcibly acquire the remaining AVE shares on the same terms as in the original tender offer.