A rapid rise in assets held by central banks, sovereign wealth funds and multinational organsations such as the World Bank will continue to support the damaged market for mortgage-backed securities, despite a decline in risk appetite, according to analysts at UBS.

Central banks have historically been among the largest buyers of mortgage backed securities, particularly those issued by the government backed agencies, such as Ginnie Mae. Appetite for these securities has been tarred by the sub-prime crisis and the perceived risk of owning them has risen sharply.