Not unheard of in corporate mergers. Another one is AT&T. When AT&T was broken up by a court (anti-trust decision), one of the "Baby Bells" that resulted was Southwestern Bell. AT&T retained only the long-distance business, and later cell phones. After a while, the Baby Bells began buying up each other, resulting in, eventually, Southwestern Bell (now SBC) and Verizon owning most of the previous Babies. Finally, SBC bought AT&T to get the cell phone business, and for corporate recognition purposes assumed the AT&T name. Good summary:
RBOCs (Baby Bells) at Wikipedia.