National Australia Bank may be taking an "all options" approach to the planned sale of its remaining 25 per cent stake in Clydesdale Bank in the UK, with the bank's board open to holding onto some or all of the stake if equity markets do not suit the bank.With minimal dissent, securities holders in NAB yesterday agreed to the demerger and a reduction in capital.NAB is well advanced in negotiating the sale price for its 25 per cent holding via an initial public offer in the UK. The price at which NAB will sell the shares will be announced on Tuesday next week (2 February), if the bank adheres to its planned timetable.The bank's chair, Ken Henry, made clear at yesterday's EGM that retention of the holding and a sale at a later time was an option the board was aware of.NAB's board may look to override the cynicism informed by global markets on the grounds of sheer necessity, one that coincides with at least one favourable trend in UK banking.Mark Carney, governor of the Bank of England, in a speech last week pointed to "the improvement in the price and availability of credit [as] one sign of the normalisation of the UK financial environment. "Another is that, after seven years of deleveraging, aggregate credit to the UK private non-financial sector has begun to grow again".