As millions of Americans struggle to hold on to their homes, Wall Street has found a way to make money from the mortgage mess.

Investment funds are buying billions of dollars' worth of home loans, discounted from the loans' original value. Then, in what might seem an act of charity, the funds are helping homeowners by reducing the size of the loans.

But as part of these deals, the mortgages are being refinanced through lenders that work with government agencies like the Federal Housing Administration. This enables the funds to pocket sizable profits by reselling new, government-insured loans to other federal agencies, which then bundle the mortgages into securities for sale to investors.

While homeowners save money, the arrangement shifts nearly all the risk for the loans to the federal government—and, ultimately, taxpayers—at a time when Americans are falling behind on their mortgage payments in record numbers.

For instance, a fund might offer to pay $40 million for a $100 million block of mortgages from a bank in distress. Then the fund could arrange to have some of those loans refinanced into mortgages backed by an agency like the FHA and then sold to an agency like Ginnie Mae, a government-owned corporation within the Department of Housing and Urban Development, which guarantees investors the timely payment of principal and interest on mortgage-backed securities backed by federally insured or guaranteed loans. The trick is to persuade the homeowners to refinance those mortgages, by offering to reduce the amounts the homeowners owe.

The profit comes when the refinancings reach more than the $40 million that the fund paid for the block of loans.

The strategy has created an unusual alliance between Wall Street funds that specialize in troubled investments—the industry calls them “;vulture”; funds—and American homeowners.

But the transactions also add to the potential burden on government agencies, particularly the FHA, which has lately taken on an outsize role in the housing market and, some fear, may eventually need to be bailed out at taxpayer expense.

These new mortgage investors thrive in the shadows. Typically, the funds employ intermediaries to contact homeowners and arrange for mortgages to be refinanced.

Homeowners often have no idea who their Wall Street benefactors are. Federal housing officials, too, are in the dark.

Policymakers have encouraged investors and banks to put more consumers into government-backed loans. The total value of these transactions from hedge funds is small compared with the overall housing market.

Housing experts warn that the financial players involved—the investment funds, their intermediaries and certain FHA approved lenders—have a financial incentive to put as many loans as possible into the government's hands.

“;From the borrower's point of view, landing in a hedge fund or private equity fund that's willing to write down principal is a gift,”; said Howard Glaser, a financial industry consultant and former official at the Department of Housing and Urban Development.

He went on: “;From the systemic point of view, there is something disturbing about investors that had substantial short-term profit in backing toxic loans now swooping down to make another profit on cleaning up that mess.”;

Steven and Marisela Alva say they do not know who helped them with their mortgage. All they know is that they feel blessed.

Last December, the couple got a letter saying that a firm had purchased the mortgage on their home in Pico Rivera, Calif., from Chase Home Finance for less than its original value. “;We want to share this discount with you,”; the letter said.

“;I couldn't believe it,”; said Alva, a 62-year-old janitor and father of three. “;I kept thinking to myself, 'Something is wrong, something is wrong. This sounds too good.”;'

But it was true. The balance on the Alvas' mortgage was ultimately reduced to $314,000 from $440,000.

The firm behind the reduction remains a mystery. The Alvas' new loan, backed by the FHA, was made by Primary Residential Mortgage, a lender based in Utah. But the letter came from a company called MCM Capital Partners.

In the letter, MCM said the couple's loan was owned by something called MCMCap Homeowners' Advantage Trust III. But MCM's co-founders said in an interview that MCM does not own any mortgages. They would not reveal the investor that owned the Alvas' loan because they had agreed to keep that client's identity confidential.

Michael Niccolini, an MCM founder, said, “;We are changing people's lives.”;

In Washington, mortgage funds are lobbying for policies that favor their investments, particularly mortgages held in securitized bundles. They want more mortgage balances to be lowered, which might help mortgage bonds perform better. Big banks generally oppose such reductions, which lock in banks' losses on the loans.

In April, about a dozen investment firms formed a group called the Mortgage Investors Coalition to press their case. One investor who is speaking out is Wilbur L. Ross, who runs a fund that buys mortgages and owns a large mortgage servicing company.

Ross said modifications that simply lower interest rates or lengthen the duration of a loan, as is typical in the government modification program, do not work well.

“;They make a payment or two, but then one night the husband and wife will sit down at the table and say, 'Do we really want to make 140 monthly payments into a rat hole?”;' Ross said.

The Fortress Investment Group, a hedge fund in New York, is one of the firms at the forefront of picking through mortgages. Fortress created a $3 billion credit fund in 2008 partly to buy loans from banks like Citigroup, which were under pressure to purge loans to raise cash.

“;They're going ahead and they are refinancing them and getting their money out right away,”; said Roger Smith, an analyst at Fox-Pitt Kelton. “;What Fortress is doing is actually good for the borrower.”; Congress, however, may not be happy that hedge funds are making money this way, Smith said.

Fortress, which declined to comment, typically buys batches of loans and works with other companies to evaluate which ones might qualify for FHA, Fannie Mae or Freddie Mac refinancing.

Sometimes Fortress works with Nationstar, a mortgage servicer and originator that it owns. Other times, Fortress uses an outside partner like Meridias Capital, a lender in Henderson, Nev., that once originated Alt-A loans, which are just above subprime.

After the mortgage market imploded, Meridias began dissecting portfolios of troubled loans for investment funds.

Because firms like Fortress purchase blocks of mortgages at distressed prices, they are able to reduce the principal amount of the loans. Nick Florez, president of Meridias, calls such transactions an “;incentive refinance.”; He said he would not agree to take a loan unless he could help the homeowner. He said he was able to reduce the loan amount by 11 percent on average.

“;I'm giving money away,”; said Florez, who is a 35-year-old Las Vegas native. “;It's really a feel-good business.”;

It is too early to know how the new loans will work.

David H. Stevens, the new commissioner of the FHA, said he was monitoring FHA lenders but did not have thorough information about which ones work with distressed investors. So far he has not seen a problem from loans coming from hedge funds.

“;They're helping to protect people in their homes and they're refinancing people from a distressed situation,”; he said.

But he acknowledged that funds have an incentive to aggressively push homeowners into federally guaranteed loans, since the investors get their money back as soon as they complete the refinancing.

Part of the risk may be determined by how the funds compensate the FHA lenders and whether the lenders are beholden to the funds for business.

David Zitting, the chief executive of Primary Residential Mortgage, the company that refinanced the Alva family's loan, said his company did not receive fees from the hedge funds.

“;They have all sorts of motivations that, frankly, we don't understand,”; he said. “;We don't do anything special for them because that's not fair lending.”;

The Alvas had to dip into their savings to qualify for their new federally insured loan, since the biggest FHA mortgage they could get was for $285,000, they said. They paid off $21,000 in credit-card and car loans, and put up an additional $29,000 for their new mortgage, depleting their already meager savings.

Brian Chappelle, a mortgage consultant, said loans to people like the Alvas, with modest incomes and scant savings, could turn out to be risky.

“;It does raise risk concerns for FHA,”; he said.

The Alvas are grateful for the help. Their home is, Marisela said, a dream come true. “;I'm very happy,”; she said. “;We never thought this was possible.”;