The Federal Housing Administration held 60,739 properties repossessed through foreclosure on its books as of December 2010, up 47% from the year before. The current value of those properties is $9.1 billion, according to the FHA book of business report released Tuesday. Combined with Fannie Mae and Freddie Mac‘s third quarter numbers, the U.S. government holds roughly 360,000 REO properties. Reselling these properties is key to driving the housing market into recovery. Estimates are wide-ranging on the size of this shadow inventory of foreclosed homes and delinquent loans still in the process. Currently, the data provider CoreLogic (CLGX) estimates it to be at roughly 1.3 million properties for the entire industry. Capital Economics on Tuesday released a report estimating it to be closer to 5.3 million homes. More could be coming in the way from the FHA alone. According to the report, nearly 600,000 mortgages are in serious delinquency. That represents 8.78% of the FHA insurance in force. With such high levels of problem loans and devalued properties after foreclosure, house prices are expected to decline throughout 2011, Capital Economics said. Write to Jon Prior. Follow him on Twitter: @JonAPrior