Detroit's Big Three cheered the action and vowed to rebuild their once-mighty industry, though they acknowledged the road would be anything but smooth as they fight their way back from the brink of bankruptcy.
The autoworkers union complained the deal was too harsh on its members, while Bush's fellow Republicans in Congress said it was simply bad business to bail out yet another big industry.
Mr. Bush, who signed the massive $700 billion rescue for financial institutions only this fall, said he was reluctant to approve yet another government bailout of private business. But he said that allowing the massive auto industry to collapse in the middle of what is already a severe downturn "could send our suffering economy into a deeper and longer recession."
Speaking at the White House, he also said he didn't want to "leave the next president to confront the demise of a major American industry in his first days of office."
President-elect Barack Obama, who takes office a month from Saturday, praised the administration action but warned, "The auto companies must not squander this chance to reform bad management practices and begin the long-term restructuring that is absolutely necessary to save this critical industry and the millions of American jobs that depend on it."
Mr. Obama will be free to reopen the arrangement from the government's side if he chooses, and the head of the United Auto Workers said the union would be appealing to the new president and the strongly Democratic new Congress on that subject.
Mr. Obama, commenting in Chicago as he named more economic Cabinet members, was noncommittal on possible changes. But he said he would "make sure that when we see a final restructuring package that it's not just workers who are bearing the brunt."
Stock prices rallied on Wall Street after Bush's announcement but faded late in the day, and the. GM shares, however, jumped 22.7 percent and Ford shares 3.9 percent. Chrysler is not publicly traded.
Some $13.4 billion of the rescue money will be available this month and next - $9.4 billion of it for General Motors and $4 billion for Chrysler LLC, the two auto giants that have said they could be facing bankruptcy soon without government help. GM is slated to receive the remaining $4 billion in loans after more money is released from the financial rescue account. Ford says it doesn't need federal cash now but would be badly damaged if one or both of the other two went under.
Under terms of the loans, the government will have the option of becoming a stockholder in the companies, much as it has with major banks, in effect partially nationalizing the industry. Mr. Bush said the companies' workers should agree to wage and work rules that are competitive with foreign automakers by the end of next year.
An assembly line worker at GM now makes $29 an hour - equal to what a Honda worker here earns and slightly less than a Toyota employee makes, reports CBS News correspondent Anthony Mason. But when you add in benefits, pensions and legacy costs, GM, which has more than 430,000 retirees, pays its average worker $69 an hour -- $20 more than Toyota.
Even with this loan, analysts say, the automakers have to take drastic steps
"That means a lot less jobs. Instead of laying off 10 to 15,000 a month, it's gonna be 25, 30,000 a month," economist Mark Zandi told Mason.
Mr. Bush also called for elimination of a "jobs bank" program - negotiated by the United Auto Workers and the companies - under which laid-off workers can receive about 95 percent of their pay and benefits for years. Early this month, the UAW agreed to suspend the program.
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Click here to read the full text of President Bush's announcement
Click here to see details of General Motor's bailout terms
Click here to see details of Chrysler's bailout terms
Underscoring the automakers' peril - and how close the bailout is cutting to the edge - GM Chief Financial Officer Ray Young said the company expects to have the first money from the government by Dec. 29, just in time to pay suppliers.
CEO Rick Wagoner said, "The timing was specifically aligned with the timing we said we needed in order to make our payments on a timely basis, so we're right on schedule there."
The deal also calls for two-thirds of the automakers' debts to be converted to stock in the companies.
Also, Chrysler, GM and Ford were to pay billions into UAW-administered trust funds that will take over paying health care bills for hundreds of thousands of retirees on Jan. 1, 2010. The trusts, called Voluntary Employees Beneficiary Associations, were to last at least 80 years.
But if half the cash is swapped for stock, the trusts might not last that long if the value of the shares declines. Swapping stock for cash payments helps the cash-starved companies, though, because they have more money to spend on operations.
Bondholders may be left with a take-it-or-leave it proposition with the government requiring them to exchange two-thirds of their holdings for stock. But they, too, could try to negotiate with the Obama administration, said Pete Hastings, an auto industry corporate bonds analyst with Morgan Keegan & Co. in Memphis, Tenn.
If they don't take the deal, GM could wind up in bankruptcy and the bondholders would get little or nothing, Hastings said.
Though auto stocks rose on Friday, the companies' stockholders aren't out of the woods.
Provisions in the bailout agreement will force GM to produce more shares, diluting the value of its stock several times over, said Efraim Levy, a senior auto industry analyst with Standard & Poor's.
There's no way the automakers will be profitable next year, said Levy. Things could be different in 2010 if the market rebounds and cost cuts kick in, he said.
Meanwhile, Treasury Secretary Henry Paulson said Friday that Congress should release the second $350 billion from the financial rescue fund that it approved in October to bail out huge financial institutions. Tapping the fund for the auto industry basically exhausts the first half of the $700 billion total.
If the carmakers fail to prove viability by March 31, they will be required to repay the loans, which they would find all but impossible. A firm will be deemed viable only if it can show positive cash flow and can fully repay the government loans.
Friday's rescue plan retains the idea of a "car czar" to make sure the companies are keeping their promises and moving toward long-term viability.
The short-term overseer will be Paulson. But the White House deputy chief of staff, Joel Kaplan, said that if the Obama team wants someone else installed to bridge the administrations, Bush is open to that.
The White House package is the lifeline desperately sought by U.S. automakers, who warned they were running out of money as the economy fell deeper into recession, car loans became scarce and consumers stopped shopping for their vehicles.
The carmakers have announced extended holiday shutdowns. Chrysler is closing all 30 of its North American manufacturing plants for four weeks because of slumping sales; Ford will shut 10 North American assembly plants for an extra week in January, and General Motors will temporarily close 20 factories - many for the entire month of January - to cut vehicle production.
Chrysler CEO Bob Nardelli said the initial injection of capital would help the company get through its cash crisis and give it a push toward eventually returning to profitability. He said Chrysler was committed to meeting the conditions set by Bush in exchange for the money.
Though Ford didn't seek short-term aid, company President and CEO Alan Mulally said, "The U.S. auto industry is highly interdependent, and a failure of one of our competitors would have a ripple effect that could jeopardize millions of jobs and further damage the already weakened U.S. economy."
Reaction on Congress was mixed. House Speaker Nancy Pelosi, D-Calif., said the bill gives U.S. automakers a chance to be "viable and competitive" but added the proposal "singles out workers and clearly puts them at a disadvantage."
House Republican leader John Boehner called the plan "regrettable." He said that granting loans for automakers was never the intention when Congress passed the $700 billion plan to rescue financial institutions and that the new plan "has failed both autoworkers and taxpayers."
Rep. Jeb Hensarling, R-Texas, chairman of the congressional oversight panel for the Wall Street rescue program, said a Chapter 11 bankruptcy reorganization, not loans rewarding decades of mismanagement, would have been a better decision.
Grover Norquist, president of the Americans for Tax Reform, sent a one-word letter to Bush that said in huge letters: "No."