NAB may sell its credit card arm

National Australia Bank, the nation's largest lender by assets, is reviewing its A$4.3 billion ($4.85 billion) credit card arm and may sell the division amid rising competition, people familiar with the matter said.

National Australia is assessing whether it should focus on more profitable units because of concern it is losing customers to rivals, said the two people, who declined to be identified because details of the review are not public.