The House sent the Senate sweeping legislation Thursday aimed at slowing the pace of foreclosures and stimulating the real estate market.

The Senate has charted a more conservative course, passing a narrower version in April. Add to that a White House veto threat, and the legislation’s prospects are murky.

House Financial Services Chairman Barney Frank, D-Mass., who authored the centerpiece of the House package, won 39 Republican votes on the floor but fell short of the two-thirds majority that would be needed to override a veto.

Members approved the legislation as three separate amendments to the Senate-passed housing measure (HR 3221).

Lawmakers adopted, 266-154, the heart of the package — an amendment that combined several major pieces of legislation. They are an overhaul of mortgage finance companies Fannie Mae and Freddie Mac, a modernization of the Federal Housing Administration and an expansion of the FHA’s loan programs aimed at helping borrowers get out from under mortgages they can’t afford.

The Senate has so far been unable to pass either an overhaul of Fannie and Freddie or an FHA expansion measure. Christopher J. Dodd, D-Conn., chairman of the Senate Banking, Housing and Urban Affairs Committee, said House passage sends a “clear signal” to the White House that Congress is intent on doing something to help alleviate problems in the housing market.

“I am working with my colleagues in the Senate Banking Committee to pass bipartisan legislation to reduce foreclosures and restore liquidity to the mortgage market,” Dodd said in a statement.

The Bush administration was outspoken this week in its opposition to the FHA rescue plan, arguing that it would bail out real estate speculators and the lenders who made bad loans in the first place.

Under the proposed expansion of FHA authority, borrowers threatened with foreclosure could get help refinancing into new, affordable fixed-rate mortgages. Both lenders and borrowers would have to voluntarily participate in the program, and the mortgage holder would have to agree to a substantial write-down of the value of the original loan. Homeowners would have to share with the government any future appreciation of their homes’ value under the new loan.

“This bill ... seeks to undo to some extent ... market failure,” Frank said, noting that required lender write-downs and profit sharing with the government should assuage concerns that the program amounted to a bailout.

Frank has said that the veto threat could be a negotiating strategy and that there are “internal debates” within the White House over what to do about the package.

While dozens from his party broke ranks, House Minority Leader John A. Boehner, R-Ohio, sided with the Bush administration Thursday, saying Democrats “are forcing responsible homeowners and taxpayers to pick up a $300 billion tab to bail out scam artists, speculators, and reckless borrowers.”

Many of the 39 Republicans who voted for the rescue plan hail from states hard-hit by rising foreclosures, including Florida and Ohio.

Ohio Republican Steven C. LaTourette, who voted for the measure, said the current crisis “calls for bold action, [and] this bill is bold.”

Rep. Ginny Brown-Waite, R-Fla., who also voted for the package, said “we cannot stick with the status quo. ... I believe we can help Americans get back into the market.”

Based on expectations for future foreclosures and potential participation from borrowers, mortgage holders and second-lien holders, the Congressional Budget Office estimated that about 500,000 borrowers would refinance under the new FHA program. The total price tag — which includes the cost of new mortgages that go bad — would be about $2.7 billion during the period from 2008 to 2013.

Designed to relieve tax burdens on new and struggling homeowners, the second piece of the housing package (HR 5720) passed more easily, in a 322-94 vote. It would establish a refundable tax credit of up to $7,500 for first-time homebuyers that would serve as an interest-free loan and would provide an additional standard deduction in 2008 of up to $350 for individuals and $700 for couples for state and local property taxes.

It would authorize an additional $10 billion in tax-exempt bonds that would be used to refinance subprime loans, finance the construction of low-income rental housing and support loans to first-time home­buyers. It would also increase the number of low-income housing tax credits.

As the final piece of the package, the House adopted, 256-160, an amendment by Brad Miller, D-N.C., and LaTourette that would prevent any provision in the bill or two major federal banking statutes — the Home Owner’s Loan Act or the National Bank Act — from pre-empting state laws dealing with residential foreclosures.

The financial services industry had strongly opposed the Miller-LaTourette language, arguing that it could interfere with federal banking regulators. Supporters of the amendment promised to modify the provision to ameliorate industry concerns.

The Bush administration has called for Congress to approve the mortgage revenue bond provisions, the FHA modernization and a regulatory overhaul of Fannie and Freddie.

Earlier, the House passed, 239-188, a separate bill aimed at easing the foreclosure burden on cities and states. Sponsored by Maxine Waters, D-Calif., the bill (HR 5818) would establish a $15 billion loan and grant program to help states purchase and rehabilitate owner-occupied foreclosed properties.

The Bush administration has also threatened to veto that bill.