AT&T Chief Financial Officer Richard Miller is leaving after guiding the ‘trivestiture’ break up of the phone giant into three separate companies, AT&T, Lucent, and NCR. Miller will stay until the end of next month while a successor is found. Miller, a former chairman and CEO of Wang Laboratories, Inc, has been a key player in AT&T’s complex 15-month restructuring, and the 56-year old has given no hint as to his next role other than to say he will work on the boards of a number of unique companies, as well as guiding and investing in young companies and non-profit work. AT&T’s CEO Robert Allen is also due to step down early this year in favor of John Walter, president and Chief Operating officer of publishing company RR Donnelley.