Ø For AT&T (which no longer is a company since the current AT&T is really AT&T in name only.
SBC Communications bought AT&T Corp. on November 18, 2005, and changed its name to AT&T Inc. (The real AT&T
is no longer...)

Well SBC was one of the RBOCs so while it wasn’t the post-Greene ATT, it is a decent chunk of the original monopoly.   Not only the old BellSouth but also Illinois, Inndiana, Michigan, Ohio, Pacific, Southwestern and Pacific Bells.    They did acquire the old long lines AT&T and wireless sytem.    Of course AT&T and already spun out what we would have called Western Electric in the days (and hence the UNIX heritage).