AMP Bank more than doubled its profit in the year to December 2008, contributing $21 million to the profit of AMP, the wealth management and insurance group reported yesterday.The bank "benefited from improved margins and reported strong growth across product lines, both retail lending and deposits" according to the very brief commentary published as pat of the AMP investor report.New home loan business increased 20 per cent to $3.1 billion. The stock of home loans increased 19 per cent over the year to $9.6 per cent, a rate of growth around double that of the wider home loan market.The deposit book increased 70 per cent to $3.4 billion as the bank chased deposits to fund mortgage growth (and replace funding from the sale of mortgage-backed securities). Policy holder deposits represent about half the deposit book.Capital allocated by AMP to the bank increased to $255 million up from $219 million, and equal to six per cent of all capital deployed by the group.