By Jesús Aguado MADRID (Reuters) -Spain’s Santander on Thursday said its Chief Executive Officer Jose Antonio Alvarez will report exclusively to the bank’s board as part of a change in its corporate governance structure while accelerating its digital transformation. Until now, Alvarez also reported to Chairman Ana Botin, who will keep her executive role. At many Spanish lenders the chairman holds executive powers and is in control of strategy while the CEO handles day-to-day business. Supervisors of euro area banks favour a division of roles between the chairman and the CEO, with sound governa…