Australian banks have “appreciably improved” their mortgage-lending standards, the nation’s regulator said, as it left the amount of additional capital banks are required to hold as a buffer against the build-up of credit risk at zero. The pace of lending to property investors is currently at around half of the regulator’s recommended levels, and higher-risk mortgages — such as those with loan-to-value ratios of over 90 percent — had fallen, the Australian Prudential and Regulatory Authority said in its annual report on the operation of the counter-cyclical capital buffer.