Fitch Ratings on Thursday revised the outlook on ANZ Group Holdings (ASX:ANZ, NZE:ANZ) unit ANZ Bank New Zealand's long-term issuer default ratings to positive from stable while affirming the ratings at "A+."

The ratings agency expects to change the anchor rating for ANZ Bank New Zealand's shareholder support rating to the long-term issuer default rating of the parent company from the viability rating once the bank is permitted to issue loss-absorbing capacity instruments to its parent, which is likely to occur by late 2028.

Differences in the regulatory capital regimes between Australia and New Zealand currently mean it is uncertain that the bank's senior creditors would benefit from the protection of the parent's resolution debt buffers, Fitch said.

The viability rating is driven by the bank's large domestic market position in New Zealand, with a market share of above 25% in loans and deposits. While Fitch expects ANZ Bank's impaired loans to rise modestly in fiscal 2026, it noted that the bank has managed credit risk well so far.

The ratings agency said the outlook may be revised to stable if New Zealand's central bank decides ANZ Bank does not need to build loss-absorbing capacity buffers through issuance to its parent, which appears unlikely.