Or in the recent case of SBC (formerly Southwestern Bell Corporation) [not to be confused with SBC for Seattle's Best Coffee, a division of Starbucks] buying AT&T and taking on the name of the rechristened company as at&t (just "lower casing" themselves and ditching the death star in favour of a blue marble.)
Then again there are other cases where a name change was affected -- MCI (Microwave Communications Incorporated) becoming Worldcom, but more than likely Worldcom was not a favourable name after the higher level hijinx with "creative" accounting bankrupted the original corporation so they changed their corporate name to that of the acquired entity (perhaps thinking that the public was too stupid to notice that it was still the same entity that screwed them out of their investment if they invested in the company.)
MCI hasn't dealt with microwave in *years* and AT&T hasn't had much of anything to do with telegraph either for that matter either.