Congress must preserve some form of U.S. guarantee on mortgages to attract private capital to the housing-finance system and stabilize a market recovering from the credit crisis, industry executives told lawmakers.

Private capital must play a bigger role in housing finance as policy makers replace the current system, which is dependent on guarantees from government-backed Fannie Mae andFreddie Mac, the executives said today in testimony prepared for a House Financial Services Committee hearing. U.S. support will still be needed to keep loans flowing to borrowers and preserve products such as 30-year, fixed-rate mortgages, they said.

Without a government backstop, there wouldn’t be enough private capital to support the $8 trillion in home loans that are funded by investors, said Michael Farrell, chief executive officer ofAnnaly Capital Management Inc., a New York real estate investment trust that owns or manages $90 billion of mortgage-backed securities.

The House panel called Farrell and other housing-industry executives to testify as they seek ways to overhaul a finance system that collapsed in 2008 amid losses on securities linked to subprime mortgages. Some economists and lawmakers have urged that any new system rely solely on private capital and be priced to reflect the risks.

“Recommendations to completely privatize miss the necessity of a government backstop to ensure consistent functioning of mortgage-backed securities markets under all economic conditions,” said Michael Heid, co-president of home mortgages for Wells Fargo & Co.

Fannie, Freddie

Fannie Mae and Freddie Mac, which own or guarantee more than half of the $11 trillion U.S. mortgage market, relied on an implied government guarantee to pool and sell mortgage-backed securities, which generated cash that could be channeled back into additional loans. The federal government seized the two companies amid soaring losses in September 2008 and promised to stand by the debt.

Since then, Washington-based Fannie Mae and Freddie Mac, based in McLean, Virginia, have survived on a promise of unlimited aid from the U.S. Treasury Department. The companies lost $166 billion on their guarantees of single-family mortgages from the end of 2007 and the second quarter of this year and have drawn almost $150 billion so far. Treasury Secretary Timothy F. Geithner has promised to deliver a plan for overhauling the housing-finance system in January.

One challenge for policy makers is how to keep money flowing into the system without the kind of open-ended commitment that left taxpayers responsible for catastrophic losses at the government-sponsored enterprises.

“The GSEs clearly did not operate with enough capital to buffer the risks they assumed,” Christopher Papagianis, managing director of non-profit research group Economics21, told lawmakers. “Policy makers should recognize that bailouts in the housing sector are inevitable if the key institutions in the space do not hold sufficient capital,” said Papagianis, an adviser to former President George W. Bush.

To contact the reporter on this story: Lorraine Woellert in Washington atlwoellert@bloomberg.net;

To contact the editor responsible for this story: Lawrence Roberts at lroberts13@bloomberg.net.