The mortgage broking platforms of Challenger (and which are being sold to NAB) reported annualised growth for the September 2009 quarter of 11 per cent. Challenger published quarterly data on funds under management and administration yesterday.System growth in home loans over the three months to August 2009 was eight per cent, according to financial aggregates published three weeks ago by the RBA.So the mortgage broking aggregation groups being sold to National Australia Bank appear to be handling an increasing amount of business, and, based on short-term trends, NAB is getting its hands on a group of distribution businesses (in Choice, Fast and Plan) that are more than pulling their weight in the home loan market.Home loans under management declined five per cent over three months to $14.9 billion, with the book down 15 per cent over one year. This is thought to reflect the continuing shift by borrowers to the more familiar big bank brands rather than a further constraint on funding from Challenger for mortgage managers.The commercial mortgage book, which Challenger will retain, was down 14 per cent over the quarter to $2.0 billion and down by 24 per cent over a year.