AllianceBernstein announced management changes Dec. 19, including making Robert M. Keith the sole head of institutional and retail distribution. He certainly will face an uphill battle. AllianceBernstein's worldwide institutional assets under management already have fallen to $224.1 billion as of Sept. 30, from $508.1 billion as of Dec. 31, 2007. According to the termination activity P&I tracks, AllianceBernstein has been terminated the most of any manager in 2011 with seven pension funds terminating it from various equity mandates. The reason most frequently cited was performance.