A report from the Melbourne-based newspaper The Age alleges that Cameron Clyne, the NAB’s new chief executive, is weighing up the benefits of holding on to the Yorkshire and Clydesdale Banks.
The paper says the UK businesses accounted for just 18% of NAB’s total earnings.
A spokeswoman for the Yorkshire Bank declined to comment.
It is understood that Clyne has since denied any plans to sell off NAB's British banking interests.