Yes, under the BA logo, it was possible to fly business class at the rear on one of the most uncomfortable aircraft I have ever encountered, up there with those Cubana's Illuyshins in terms of passenger comfort. Until quite recently these dreadful aircraft were offering business class on CSA (Czech) and LOT (now EuroLot, Polish), also from the back. As I recall in all cases the seating was the same 2+2, same pitch throughout, except BA put in about 5cm extra for the back rows. However the only reason you'd get an empty seat next to you would be if no one else volunteered for the punishment. On LOT in particular there is a tradition of people spreading themselves out after boarding has nearly completed and the cabin crew had their work cut out explaining why going backwards meant they were venturing into the hallowed portals of bizness class. One of the unexpected outcomes of LOT nearly going bankrupt was that these aircraft were removed from the fleet, goodness knows where they went. BA and CSA had curtains, LOT did not. Noisy, cramped and with no space for humans let alone baggage. There were other ATRs in this series that had front entrances, which made life even more confusing.