The action by the bank is likely to increase pressure on other lenders to declare their own moratoriums. Lawmakers and state law enforcement officials have been widely calling for such halts.

Representative Edolphus Towns, the New York Democrat who is chairman of the House Committee on Oversight and Government Reform, applauded Bank of America’s move and said, “I expect to see every other responsible banking institution follow their lead.”

Senator Harry Reid, the Nevada Democrat who is the Senate majority leader, thanked Bank of America “for doing the right thing” and urged other lenders to follow suit.

Last week, Bank of America halted foreclosures in 23 states where evictions need court approval, saying it was reviewing its filings in the wake of disclosures about improperly prepared documents. Those states include Florida, Illinois and New York.

Bank of America services 14 million loans. More than 14 percent of those loans are past due or already in foreclosure.

The lender said Friday that it would resume foreclosures and sales when its assessment was “satisfactorily completed,” but gave no indication of when that would be.

In the meantime, hundreds of thousands of its customers who are in foreclosure have a little unexpected breathing room, while foreclosed homes that normally would have come to market will be delayed.

Last week, the lender halted foreclosures in 23 states where evictions need court approval, saying it was reviewing its filings in the wake of disclosures about improperly prepared documents.

Other lenders that have frozen foreclosures and foreclosure sales are JPMorgan Chase, GMAC Mortgage and PNC Financial.

Mortgage lenders are under fire because of evidence that some foreclosure documents were improperly prepared as lenders tried to reclaim as many houses as possible. The revelations have prompted a growing furor, including investigations by a half-dozen state attorneys general and a federal investigation.

Friday’s action by Bank of America imposes the freeze in several of the states where foreclosures are the highest, including Arizona, California and Nevada.

“Our ongoing assessment shows the basis for foreclosure decisions is accurate,” the lender said in a statement.

The foreclosure crisis comes at a particularly vulnerable moment for the housing market. Sales slumped this summer, despite the lowest mortgage rates in decades. Most economists expected housing prices to start falling again this winter, continuing a decline that had pushed

Distressed sales, including foreclosures, make up about a quarter of the market. If those deals do not happen, the market could suffer its own freeze.

“The impact could very well be a decline in housing prices,” said Anthony Sanders, a professor of real estate finance at George Mason University. “Halting foreclosure sales limits the inventory coming back on the market, but uncertainty about future housing prices usually results in a decline. More households will stay out of the housing market.”

On Thursday, the White House said that President Obama would not sign a bill that critics suggested could facilitate foreclosure fraud. His pocket veto effectively kills the measure, since lawmakers, who are out of town until after the Nov. 2 midterm elections, are not in position to override his decision with a two-thirds vote of the House and Senate.

The bill would have mandated that notarizations of mortgages and other financial documents done in one state, including those done electronically, be recognized in other states. By the time the bill arrived at Mr. Obama’s desk, however, it was caught in the controversy over major institutions’ acknowledgment of problems in processing documents for tens of thousands of foreclosures.