WASHINGTON -- The Senate is poised to vote as early as this week on a package of housing initiatives that would mark lawmakers' most comprehensive effort yet to deal with record numbers of foreclosures and a housing slump that is weighing on the economy.

The legislation includes a regulatory overhaul for government-sponsored mortgage investors Fannie Mae and Freddie Mac, a $300 billion program to refinance struggling borrowers and a combination of government grants and tax credits to help homeowners.

Sen. Christopher Dodd (D., Conn.), chairman of the Senate Banking Committee, and his Republican counterpart, Sen. Richard Shelby of Alabama, said Tuesday they had agreed on a bill. The deal, which includes changes negotiated by Sens. Dodd and Shelby over the last several weeks, should allow the Senate to pass the measure this week.

The Senate measure differs enough from a version of the legislation passed by the House that lawmakers may struggle to meet a self-imposed deadline to deliver a major housing-relief bill to President Bush by July 4. "We've got to be careful here; this thing could collapse and if it does, you may be talking about them waiting until next year," Sen. Dodd told reporters at a news conference.

House Financial Services Chairman Barney Frank (D., Mass.) said in an interview the House won't simply accept the Senate bill but that it moves the two sides "close conceptually." He said the housing legislation may not be finished by July 4.

The Senate bill would expand the size of single-family mortgage loans that can be acquired or guaranteed by Fannie Mae and Freddie Mac to $625,000 from the $550,000 set in an earlier bill approved by the banking committee. The current limit on such loans is about $730,000. That represents a temporary increase enacted by Congress earlier this year. The loan limit is due to revert to $417,000 at the end of this year unless Congress acts.

The compromise wording also would let the two companies hold these "jumbo conforming" loans as investments rather than selling all of them to investors in the form of securities.

The loan limit has been a major sticking point, with Republicans and Democrats from areas with high-cost real estate pushing for higher limits for Fannie Mae and Freddie Mac, as well as for the Federal Housing Administration.

Raising the level to $625,000 is a good step, said Sen. Mel Martinez (R., Fla.). "I would like to see Fannie and Freddie play a role in the higher-priced markets like Florida," Sen. Martinez said.

Write to Michael R. Crittenden at michael.crittenden@dowjones.com

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