The chief executive of National Australia Bank subsidiary Clydesdale Bank, David Duffy, is in Australia this week to meet investors and spruik a listing if his bank by the end of the year.Fairfax Media reports that up to 80 per cent of Clydesdale's stock would be spun off to NAB shareholders and the rest would be sold to institutional investors in an IPO in the United Kingdom. The demerger and IPO was first outlined by the bank in May.NAB chief financial officer Craig Drummond said yesterday that the plan was "well advanced" and that the bank would provide more details at its annual results presentation next month.The Spanish bank Sabadell has been touted as a buyer of Clydesdale but Drummond said the demerger and IPO remained the main goal."Obviously, if there was something exceptional from a shareholder value perspective we'd need to look at it. But to be very clear, our current intention, our strong preference at the moment, is to go down a demerger and IPO," he said.Clydesdale, which NAB bought in 1987, has been a drag on shareholder returns for some time. Current return on equity is around eight per cent and its cost-to-income ratio is 71 per cent.Duffy said the bank had the opportunity to grow in retail and small business lending, as its larger rivals were facing a tougher regulatory environment.Duffy told The Australian: "We're talking about a strong marketplace - quite a vibrant economy. Overall the credit environment is strong."