FACTBOX - Key provisions of U.S. housing rescue bill

(Reuters) - With White House encouragement, the U.S. Congress on Saturday gave final approval to a housing rescue bill that will backstop Fannie Mae and Freddie Mac, create tougher oversight of the mortgage finance giants and spend billions to prevent home foreclosures.

The sweeping legislation, approved by the House of Representatives on Wednesday and the Senate on Saturday, has moved with uncommon speed and could be in place by next week. President George W. Bush and key lawmakers have said they hope the legislation will help restore confidence in a U.S. housing finance system battered by a wave of failing loans.

Following are some key provisions of the legislation:

* Fannie Mae and Freddie Mac, which each have a $2.25 billion (1.13 billion pound) line of credit with the Treasury, would see their current government loan limit raised until January 2009.

* If the companies' financial condition were to reach a crisis, Treasury could take an equity stake in either company. That power, too, would expire in January 2009.

* There is a better-than-even chance that the emergency measures will not be needed, meaning there will be no cost to taxpayers. If the lifeline is required, the Congressional Budget Office said, there is a 5 percent chance that the companies may need $100 billion but more likely would need $25 billion.

* A new regulator would be created with broad powers to set capital levels for Fannie Mae and Freddie Mac, with the Fed's consultation.

* The Federal Housing Administration would be authorized to refinance up to $300 billion in failing mortgages with Fannie Mae and Freddie Mac covering billions in expected losses.

* Fannie Mae, Freddie Mac and FHA would be permitted to purchase loans as large as $625,500 in high-cost areas -- a big increase from the $417,000 cap typically in place.