Westpac, ANZ, ASB and BNZ all have parent companies that are domiciled and regulated in Australia they are actually all majority American owned. ANZ is 61 per cent owned by US shareholders with just 17 per cent of shares held in Australia. Westpac is 58 per cent US owned with 22 per cent held by Aussie shareholders. CBA and NAB (the parent companies of ASB and BNZ respectively) have similar ownership profiles - all dominated by US shareholders with Australia a distant second.