The Australian Office of Financial Management has sold about A$300 million of its holdings in residential mortgage-backed securities. The Government's finance arm announced yesterday that it had sold securities from Apollo, SMHL and Torrens trusts.The securities were from 2009 and 2010 issues. They were sold at an effective margin of 75 basis points over the one-month bank bill swap rate and they had a remaining weighted average life of 2.5 years.The AOFM said the sale was made in accordance with the Treasurer's directions, which allow the organisation to adjust its holdings.From 2008, when the AOFM started providing support for the RMBS market, it invested about $14.5 billion in the market, made up of 67 securitisation deals issued by 20 lenders.In April the Treasurer announced that the investment program would come to an end. This followed an improvement in RMBS market conditions that saw a number of issues priced without AOFM support.The AOFM has sold securities throughout the life of the investment program. It announced sales in February, in November last year and in March last year.