Choice doubles Challenger mortgage book 23 November 2007 5:22PM Ian Rogers The chair and chief executive of Challenger Financial Services Group barely mentioned the fact or consequences of the disruption in credit markets in prepared remarks for the company's annual meeting and lodged with the ASX.The only insight from those documents is that Challenger acquired $21.5 billion of mortgages under administration courtesy of the group's purchase of Choice Aggregation Services, a mortgage aggregator.Challenger said in September it agreed to pay $163 million for Choice Aggregation Services. As part of a wider investment in the mortgage broking sector the group said it would acquire the 85 per cent of Plan Australia that it does not already own and it will take a 19 per cent stake in Fast, a Western Australian aggregator.At the end of June 2007 Challenger had $23 billion of mortgages under management and its mortgage operations reported earnings before interest and tax of $90 million.