Debt securities continue to feature more prominently in the asset allocation choices of Future Fund, the Australian government entity investing past budget surpluses to part fund future public service pensions.The fund said it invested $14.5 billion, or 24.1 per cent of its assets (ignoring its overweight position in Telstra shares) in debt securities as of September 2009.This is a rise from $12.5 billion, or 23.1 per cent of its investment portfolio, at the end of June.