January is usually a slow month for mortgage sales and last month was no exception. Mortgage aggregator AFG reported yesterday that January volumes were down 15 per cent on December's and 37 per cent on November's sales, which was its peak month for 2011.AFG's mortgage brokers wrote 4736 loans in January compared with 5576 in December and 7492 in November.The value of loans written in January was A$1.8 billion - down from $2.2 billion in December and $2.9 billion in November.The good news is that the holiday slowdown was not so bad as it was in January last year, when volumes fell to 3583 and the value of loans was a mere $1.3 billion. Business was badly affected by the Queensland floods of 2010-2011.While the January figures were affected by seasonal factors, the longer term trend is for slower home loan market growth. Australian Prudential Regulation Authority figures published this week show that total bank mortgage books grew by 5.9 per cent in the year to December 2011 - down from 8.1 per cent for the year to December 2010.According to AFG, the major banks maintained their dominant position in the market, with a 79 per cent share in January.Demand for fixed rate loans, at 18.6 per cent of the total, held up well following last year's two interest rate cuts.