After spending less than two years in the job, ASB Bank's managing director and chief executive officer, Charles Pink, has resigned from his position citing personal reasons.Retail banking head Ian Park, an ASB executive for 23 years, will take up the role of acting CEO until a permanent replacement is appointed.Pink had joined ASB from Barbados-based FirstCaribbean International Bank.It isn't clear if Pink plans to stay on in New Zealand, take up a position overseas, or is, in fact,  leaving for personal reasons.