Mike Robertson leaves Citibank for old stomping ground

Mike Robertson walked away from Citibank last Friday to rejoin Standard Chartered in a new role as the bank's chief operating officer for Africa based in London. He leaves the regional position of e-business head for Citibank's cash management and trade after three years. The post remains vacant and, as yet, there is no indication of a replacement.An American, Robertson has worked with Standard Chartered in London before. His move is said to be motivated by personal reasons - he has t…