Fragile Allegiance was developed by Gremlin Interactive, which was later acquired by Infogrames (Atari). I couldn't find any details of the acquisition though.
The only interesting thing I have found online is that the owner of the registered trademark Fragile Allegiance is Interplay, who published Fragile Allegiance. However, the only copyright note I've found was in one installation .ini file, claiming it for Gremlin.
What are the common business practices when it comes to old, unused IPs? What do publishers/developers actually need to legally claim an intellectual property? Does anyone have an experience with contacting big publishers with copyright/IP inquiries?