Since taking on the chief executive role at Investec Bank Australia two years ago, David Clarke has been shifting the revenue base of the business from interest to non-interest income. The most obvious change is the scaling back of the bank's property finance activities.Clarke has been building the bank's strength in areas such as corporate advisory, capital markets and securities. The strategy has yet to make an impact on the bottom line, however.On Friday, Investec reported a pre-tax profit of A$2.1 million for the year March, down from $30.2 million the previous year.Operating profit before impairments was $61.1 million, compared with $81.5 million for the previous year.The bank has been plagued by bad debts for the past few years, largely due to property loan impairments. The bad debt charge for the year to March was $49.3 million - three per cent lower than the previous year.Clarke said the bank would be dealing with its legacy book for another two years. It also has about two years to go before the completion of its restructure."Interest income was $119 million and non-interest income was $83 million. Our aim is for that mix to reverse," he said.Clarke said the strategy was for Investec to be a collection of niche finance businesses. The most highly developed of these is resources, where it already advises small and mid-cap resource companies, lends to them, provides primary and secondary equity capital services, offers hedge services and produces research.It also has a specialist professional finance business that services medical practitioners. It is developing a specialist funds business and has already put in place an aircraft leasing fund, a real estate fund and a renewable energy fund.Clarke said the bank's corporate advisory team has been involved in plenty of M&A activity over the past year, including advising private equity group Blackstone on its bid for the Spotless Group. It has also advised Aspen Pharmaceuticals, on its $900 million acquisition of Sigma Pharmaceuticals; Laundy Hotel Group, on its acquisition of the Redcape Property Fund and National Leisure Group pubs; as well as Spark Infrastructure on its restructure.The bank has a strong private client business, particularly on the deposit side. Private client deposits have increased 31 per cent, to $1.9 billion, which makes up 58 per cent of the bank's loan funding.Clarke said Investec would not get out of property finance but it would play a smaller role in the bank's overall business mix in the future. "We are still doing property loans, but the businesses that we lend to need substance. They need a track record. And we are looking for customers who will do other things with us, such as advisory and liability management.