Non-bank lenders may be able to market more loans with higher loan to valuation ratios assuming they can attract the Australian Office of Financial Management and other investors to buy into their loan pools.The AOFM yesterday published its request for proposals in its second round of investment in mortgage-backed securities. To date the AOFM has invested $2 billion in four portfolios, three originated by non-bank lenders (FirstMac, Challenger and Resimac) and one by Members Equity Bank.The primary change in criteria for this selection round is that the AOFM removed the previous requirement for the weighted average loan to valuation ratio of the mortgage pool to be no more that 70 per cent. This criterion has meant that funders have restricted their maximum LVR on new lending in many cases to 80 per cent (though some lenders are adopting this policy in any event thanks to more caution over the outlook for property prices).Once again the AOFM will cap its investment at $500 million and the government agency's aim is for proponents to attract additional investors.The AOFM said it expects to issue at least four mandates under this second round RFP and aims to fund mortgage pools in February.It said it may undertake a third round of funding in April or May.