The Australian Prudential Regulation Authority (APRA) wrote to banks and confirmed plans to formally introduce a three-tiered approach to proportionality in its prudential framework for banking, according to a Wednesday statement.

Effective July 1, APRA said it will introduce a third tier of "Most Significant Financial Institutions" for banks with total assets of over AU$300 billion, raise the asset value threshold for banks to qualify as a "Significant Financial Institution" (SFI) to AU$30 billion from AU$20 billion, and automatically provide a 12-month transition period when a regulated institution moves to a higher tier.

The regulator said the planned move was in response to the Council of Financial Regulators' review into small and medium-sized banks, undertaken in consultation with the Australian Competition and Consumer Commission.

APRA also committed to providing non-SFIs with additional time to comply with new and revised prudential requirements when appropriate.

Judo Capital Holdings' shares shed about 1% in recent Wednesday trade.