ING Australia could potentially embark on an aggressive push to boost its market share in key lending markets after Australia's prudential regulator granted the bank the right to use internal risk models to calculate its regulatory capital.The decision, announced by the Australian Prudential Regulation Authority, puts ING on an equal footing with the four major banks and Macquarie in terms of the regulatory capital it must put aside for each loan it writes.With its new accreditation, the risk weight applied to most standard home loans made by ING will fall from 35 per cent to around 25 per cent.The capital requirements on ING will also reduce for consumer and business lending products.The risk discount means that ING's capital costs on new lending will fall sharply.APRA said in a statement that its decision followed suggestions from the Murray Inquiry in 2014 to make the accreditation process for internal modelling more accessible to approved deposit taking institutions.The regulator said that ING's accreditation would take effect from the quarter ending in June.