Structured finance lender and investor Mariner Bridge, yesterday announced a full year net profit of $4.1 million, offset by a $10.4 million provision for the company's investments in the US securitisation market.Including a further $5 million provision for 2008, Mariner will have now written down its US securitised portfolio by 39 per cent, leaving a face value of less than two thirds at 61 per cent.Karen McGregor, chief financial officer and company secretary at Mariner Bridge, said "There is a possibility that if the US securitisation market deteriorates further, we may have to make an additional provision, and if that happens it may impact short term profitability."We have already reflected on the lessons learnt from this investment, and we are looking to reduce our exposure to the US securitisation market by not making any further investments in this segment. Our exposure will naturally fall as a per cent of the total investment portfolio as the investment portfolio grows."US securitisation currently makes up nine per cent of the investment portfolio.McGregor continues, "We have provided provisions for $10.4 million to 30 June 2007, and then provided an additional $5 million to financial year 2008, which we are confident can be absorbed within our 2008 profitability numbers."We think that is the appropriate level given all the information we have as at today."About 45 per cent of the Mariner investment portfolio is leasing, comprising aviation and shipping, with some small ticket leasing.McGregor said the investment portfolio does not lack diversification due to the strong leasing focus, as within each of the leasing sectors there are multiple transactions, "So we would say it's quite a diversified portfolio within leasing exposure."Mariner expects to increase total investments under management to $375 million by December 2007, which would require the investment portfolio to increase by a fifth from the $309 million as at 8 August 2007.To fund the expansion, McGregor said, "In the medium term our growth will be funded by increased debt. We have $130 million of committed credit facilities, which as at today (August 9) are drawn to $59 million, and we expect to be able to use the available facilities plus an increase in debt during the financial year to fund growth."The key for us is investment selection, and we are confident with the investments we are seeing already, that we will continue to be able to identify assets across the four asset classes, possibly more in our leasing, property and renewable energy transactions that will both deliver us the volume of transactions and the return we are looking for".The four asset classes are property, infrastructure, leasing and fixed income, which comprises the faltering US securitisations.