In the largest deal to date aimed at addressing the housing meltdown, federal and state officials on Thursday announced a $26 billion foreclosure settlement with five of the largest home lenders.

The deal settles potential state charges about allegations of improper foreclosures based on robosigning, seizures made without proper paperwork.

The settlement includes the Justice Department and the U.S. Department of Housing and Urban Development, as well as 49 state attorneys general -- all but Oklahoma.

"We are using this opportunity to fix a broken system," said U.S. Attorney General Eric Holder at the news conference announcing the settlement.

The settlement sets up a federal monitor to oversee the process and try to prevent roadblocks and red tape that tripped many homeowners seeking help in earlier programs designed to address the housing crisis.

President Obama said the settlement will "begin to turn the page on an era of wrecklessness that has left so much damage in its wake."

"No action, no matter how meaningful, is going to by itself entirely heal the housing market," he said in separate remarks at the White House. "But this settlement is a start."

Most of the relief will go to those who owe far more than their homes are worth, known as being underwater on the loans. That relief will come over the course of the next three years, with the banks having incentives to provide most of the relief in the next 12 months.

"This settlement is about homeowners, homeowners in distress," said Iowa Attorney General Tom Miller at the news conference with state and federal officials.

Principal reduction: At least $17 billion will go to reducing the principal owed by homeowners who are both underwater and behind on their mortgages.

The agreement calls for principal reduction for as many as 1 million people. But it's unlikely the money will go that far, because many people need more than the $17,000 average reduction that would result if the money is split among 1 million homeowners.

At the same time, total principal reduction could go higher -- to as much as $34 billion -- since the agreement requires deeper principal reductions for the most troubled loans.

Refinancing: Officials say up to 750,000 other underwater homeowners who are current on their mortgages will be able to refinance their current loans at lower rates. They will not receive a reduction in principal, but with mortgage rates now near record lows, they could receive substantial savings on their monthly payments.

The settlement sets aside $3 billion to account for the reduced interest payments the banks will receive after the refinancing.

Robosigning payments: About $1.5 billion of the settlement will go to homeowners who had their homes foreclosed upon between Jan. 1, 2008 and Dec. 31, 2011, and who meet other criteria. They will receive up to $2,000 each.

Accepting that payment does not preclude homeowners who lost their home in an improper foreclosure from suing the bank to recover damages, Donovan said.

Participating banks: The five mortgage servicers that are parties to the settlement -- Bank of America, JPMorgan Chase, Citigroup, Wells Fargo and Ally Financial -- will pay a total of $5 billion to the states. Some of that money will go to foreclosed homeowners and the rest to the states.

Federal officials say negotiations are underway to expand the settlement to nine other major servicers, which would raise the overall value of the settlement to $30 billion.

Related settlements: The deal spurred pacts between the authorities and banks in similar cases.

Oklahoma Attorney General Scott Pruitt announced a separate $18.6 million settlement that addressed homeowners whose homes were foreclosed through improper means, but did not provide help to those whose mortgages were underwater. He said he believes the broader agreement "overreached" the authority of both federal and state governments.

"We had concerns that what started as an effort to correct specific practices harmful to consumers, morphed into an attempt by President Obama to ...fundamentally restructure the mortgage industry in the United States," Pruitt said.

The Federal Reserve said it had reached an agreement with the five banks to pay a $766.5 million in sanctions related to their servicing practices.

And Loretta Lynch, the U.S. Attorney in Brooklyn, N.Y., announced a $1 billion settlement with Bank of America to resolve claims of underwriting and mortgage origination fraud by BofA and mortgage lender Countrywide Financial, which BofA bought in 2008.

The $26 billion deal announced Thursday is the second biggest settlement ever involving states. It trails only the $206 billion pact in 1998 with the tobacco industry.

And it dwarfs any settlements that major Wall Street firms have reached to resolve other allegations of misdeeds related to the financial markets meltdown and the Great Recession.