Bush has hailed the package amid a worsening housing market downturn and a dramatic slowdown in American economic growth.

The stressed economy lost jobs last month for the first time in over four years and a Wall Street credit crunch, triggered in part by rising home foreclosures, has roiled global financial markets in recent months.

"This plan is robust, broad-based, timely, and it will be effective. This bill will help to stimulate consumer spending and accelerate needed business investment," Bush said in a statement released Thursday by the White House.

The plan is valued at around 150 billion dollars and crammed with temporary tax rebates and business incentives.

Tens of millions of Americans are likely to receive tax rebate checks in their mailboxes in coming months after Bush gives the stimulus his official blessing.

Treasury Secretary Henry Paulson also welcomed congressional approval of the package, saying it would inject money into a stressed economy.

"This package of payments to individuals and incentives for businesses to invest will support our economy as we weather the housing downturn," the Treasury secretary said.

Democratic and Republican senators had sparred over different incentives after the House of Representatives passed an initial version of the plan last Tuesday.

The Democratic-controlled Senate approved an amended version of the House measure Thursday which senators changed to include tax rebates for low-income retirees and military veterans.

House lawmakers met in an evening session to quickly approve the final amended package.

The plan calls for tax rebate checks of up to 600 dollars for individual taxpayers and up to 1,200 dollars for couples, plus additional cash for dependent children.

It also expands financing opportunities in the housing market by allowing Fannie Mae and Freddie Mac, two mortgage finance companies, to purchase or guarantee mortgages larger than 417,000 dollars up to 729,750 dollars.

Lawmakers said it will not benefit wealthy Americans, as tax relief begins to phase out for individuals earning 75,000 dollars and for married couples with a combined income above 150,000 dollars.

It will, however, provide "unprecedented" help to some 35 million families who work but make too little to pay taxes, they said.

People who earned at least 3,000 dollars in 2007 are eligible for 300 dollars per individual or 600 dollars per couple, lawmakers said.

Democrats and lawmakers from Bush's Republican Party applauded the plan.

"Today's agreement is a victory for a better, more effective economic stimulus. Economists agree that consumer spending, fueled by tax rebates, can boost America's economy," said Democratic Senator Max Baucus.

Republican Senator Mitch McConnell said:"This is not a victory for Republicans or Democrats. This is a victory for the American people."

It's unclear, however, how much of a boost the vast package will give the troubled economy. Some economists have voiced doubt about whether the plan will deliver a needed shot-in-the-arm to growth.

Its success will depend in part upon whether Americans spend their rebate checks and boost consumer spending or stuff them in bank accounts.

Political concern about the economy has increased amid worries the country is on the cusp of a recession.

The Federal Reserve has slashed interest rates since September in a bid to fire up economic momentum, which slowed significantly to a 0.6 percent annualized crawl during the fourth quarter of last year.

Paulson said the government could start mailing out tax rebates to those eligible to receive them by early May.

A French trader was ordered to be jailed Friday while investigations continue into the billions in losses he allegedly caused at Societe Generale bank.

A probe into the case broadened as well, with police taking into custody a brokerage employee who reportedly had been in contact with Jerome Kerviel, the 31-year-old futures trader.

Prosecutors sought to jail Kerviel to keep him from contacting accomplices, if he had any, and from jeopardizing what promises to be a long and complex investigation.

Judges allowed Kerviel to go free last month after his lawyer argued he did not pose a flight risk.

It was unclear if Kerveil had been taken into custody Friday.

News that police had arrested a second person, an employee at a brokerage arm of Societe Generale, again raised questions about whether Kerviel acted alone.

Societe Generale, one of France's biggest banks, has said Kerviel did not appear to have accomplices when he made massive unauthorized bets on European futures markets that the bank said cost it more than $7 billion to unwind.

The daily newspaper Le Monde reported Friday, however, that the bank has turned over new evidence, including a message sent to Kerviel through the bank's computer system by the broker now in custody.

The message, sent Nov. 30, read: "You have done nothing illegal in terms of the law," the newspaper reported.

The employee from brokerage Newedge, a 50-50 joint venture between Societe Generale and bank Calyon, was taken into custody Thursday and was still being held Friday, according to a judiciary official who asked not to be identified because of the sensitivity of the case.

Societe Generale spokeswoman Joelle Rosello confirmed the employee was in custody. "We are cooperating closely with police," she said.

Le Monde said Kerviel passed some trades through the brokerage, and that police suspect that the brokerage employee was aware of Kerviel's activities. It said the brokerage was searched Thursday.

Societe Generale announced Jan. 24 that it lost 4.82 billion euros ($7.09 billion) cleaning up Kerviel's unauthorized transactions. It said Kerviel overstepped his authority and bet 50 billion euros ($73 billion) -- more than the market value of the entire bank -- on futures in European equity markets. It also said he did not appear to have profited personally from the trades.

Since the scandal become public, Societe Generale has faced speculation that it could be bought out or broken up, and about how Kerviel's activities went unnoticed or ignored.

Investigating judges have filed preliminary charges against Kerviel for forgery, breach of trust and unauthorized computer activity.

The U.S. Court of Appeals for the District of Columbia Circuit negated a rule known as cap-and-trade. That policy allows power plants that fail to meet emission targets to buy credits from plants that did, rather than having to install their own mercury emissions controls. The rule was to go into effect in 2010.

The court struck down the cap-and-trade policy and the Environmental Protection Administration's plan to exempt coal- and oil-fired power plants from regulations requiring strict emissions control technology to block emissions.

New Jersey and many other states challenged the policy in federal court. The agency defended the rule, saying it represented the nation's first attempt to control such emissions and would reduce mercury emissions by 70 percent.

The three-judge panel agreed with the states that the EPA did not have the authority to exempt the power plants. The court unanimously ruled that EPA's arguments were "not persuasive."

Mercury is a powerful neurotoxin that accumulates in fish and poses the greatest risk of nerve and brain damage to pregnant women, women of childbearing age and young children. Emissions of mercury total about 48 tons a year, most of it in the form of air pollution that winds up in waterways.

The states argued that the cap-and-trade system would endanger children near some power plants that pollute but which also use credits to do it legally.

"This means the EPA is going to have to go back and do a real job of regulating all the toxics coming out of these plants," said attorney James S. Pew, who argued on behalf of several environmental organizations that filed documents in the case.

Joining New Jersey in the lawsuit were: California, Connecticut, Delaware, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, New Mexico, New York, Pennsylvania, Rhode Island, Vermont and Wisconsin.

It was not immediately known who brought Thursday's action, known as an ex-parte motion.

Two attorneys for Spears' father James — who has been named as her conservator — were in court along with Spears' court-appointed attorney and an attorney for the conservatorship. A conservatorship is created when a court determines a person can no longer care for his or her own affairs.

The hearing came a day after Spears was suddenly released from a psychiatric hospital, drawing objections from her parents.