...March 30, 2021 - Australian major bank Westpac Banking Corp. (Westpac) is considering a demerger of its New Zealand banking subsidiary, Westpac New Zealand Ltd. (WNZL). - In our view, WNZL is likely to remain a part of the Westpac group in the next two years. Even if Westpac proceeds with the demerger, we expect its creditworthiness to remain unchanged. - In our view, WNZL remains highly likely to receive extraordinary financial support from Westpac. Nevertheless, we see increased downside risks to our ratings on WNZL due to the possibility of a reduced strategic importance of WNZL to the Westpac group. - We are affirming our '##-/A-1+' long- and short-term issuer credit ratings on Westpac and its core subsidiaries, including WNZL. - The outlook is negative, reflecting a one-in-three likelihood that we will lower our long- and short-term ratings on the bank in the next two years. The negative outlook on WNZL reflects the negative outlook on Westpac and the downside risk to WNZL's strategic...