After several years of strong growth in its corporate and asset finance division, Macquarie group has reported a dip in the performance of the business.The division reported lower income, lower earnings and a reduction in the size of the portfolio during the September 2016 half.Corporate and asset finance provides corporate and commercial real estate loans around the world. Its asset finance business covers aircraft, motor vehicles, technology, healthcare, manufacturing, energy, rail and mining equipment.The division is what Macquarie refers to as one of its "annuity style" businesses. The group focused on building up these businesses (which also include its asset management and banking divisions) after the financial crisis.Macquarie has beefed up the CAF division with a number of acquisitions, including AWAS Aviation Capital and the Esanda auto dealer finance business last year. It acquired UK dealer finance business Advantage last year, Euro Rail in 2013 and a portfolio of mining equipment assets in 2012.In the wake of the financial crisis it bought Ford Credit and GMAC.Since 2010, the division has tripled the value of its assets and earlier this year the co-head of the division, Garry Farrell, said he was on the lookout for new market opportunities.Corporate and asset finance contributed net profit of A$521 million to the group's September half result - down 15 per cent on the same period last year.Operating income fell three per cent to $835 million. The value of the division's portfolio, at A$38.1 billion, was up on last year but fell three per cent half-on-half.Macquarie said in its financial report that the lower income was "due to timing of repayments and realisations as well as lower loan volumes."Macquarie Group chief executive Nicholas Moore said: "We are down from last year on lending.  We think that will pick up."We wrote new business but at a lower level. It is very much about looking at the returns we can make from deploying capital."That thinking is driving a reset in Macquarie's once multi-faceted mortgage division.The group sold its US mortgage interests (at a loss) over the most recent half and has its Canadian mortgage arm winding down.In Australia, though, the mortgage portfolio increased four per cent to $28.6 billion from September 2015, "representing approximately two per cent of the Australian mortgage market."Rich deposit flows mean Macquarie has not needed to fund new business through any PUMA mortgage-backed securities this year.