Australia’s banks are exploiting official interest rate rises to gouge ever increasing profits from customers, according to The Australia Institute.

A new Institute study, A licence to print money: bank profits in Australia, reveals that since deregulation in 1983 banks have increased their share of the lending market from 50 to 90 per cent.

In 2009 this earned the big four banks $35 billion in underlying profits; or the equivalent of just under three per cent of GDP.

Senior Researcher, David Richardson, said the rush by the banks to increase their lending rates this week following a rise in the official cash rate is a prime example of how banks are able to exploit their market share at the expense of customers.