TORONTO - With an American promise of massive aid for General Motors and Chrysler, Canada could be on the hook for a $4-billion-plus rescue package of its own, with the possibility of tens of billions of additional federal and provincial dollars down the road.

The federal and Ontario governments promised last week to match one-fifth of any U.S. bailout, in proportion with Canada's share of North American auto production.

The Bush administration announced Friday it will provide US$17.4 billion in emergency loans to the beleaguered automakers, meaning Canada will have to provide C$4.2 billion to the carmakers' Canadian subsidiaries if it sticks to its promise.

But it's widely assumed the aid announced Friday is simply a bridge to allow the automakers to survive until U.S. president-elect Barack Obama takes office in January, when a larger bailout will be announced.

No one knows how much the rescue of the Detroit automakers will end up costing the U.S. government.

"I would estimate that by the time this is all over, they could end up spending $150 billion, even more, $200 billion over the next several years," said Peter Morici, a business professor at the University of Maryland and an outspoken critic of the Detroit Three.

"These companies are not going to be restructured that easily, they're not going to meet the terms of this agreement all that quickly, and the Obama administration is going to be hard-pressed to cut them loose."

Morici's analysis suggests the federal government and the government of Ontario, where the Canadian car industry is centred, could eventually contribute C$48 billion. This figure alone would surpass Canada's largest ever annual federal budget deficit -- $42 billion in 1993.

Meanwhile, industry analyst Bill Pochiluk of AutomotiveCompass LLC said he thinks the bailout will cost the U.S. government "at least" US$60 billion, suggesting the Canadian figure will be closer to C$15 billion.

The Ontario and federal governments didn't provide firm figures on Friday, but Prime Minister Stephen Harper and Ontario Premier Dalton McGuinty were set to make an announcement Saturday.

Spokesmen for Harper and Ontario Economic Development Minister Michael Bryant called the Bush bailout "good news."

Bush pledged emergency loans in exchange for concessions from the deeply troubled carmakers and their workers. He called on United Auto Workers union members to accept wages and work rules competitive with foreign automakers by the end of next year.

Canadian Auto Workers president Ken Lewenza applauded the Bush decision but said workers are being unfairly targeted.

"I'm glad the U.S. president recognized the importance of the auto industry in the United States, but I am extremely frustrated that he concentrated a great deal of his discussion on UAW contracts, because this isn't about UAW contracts," Lewenza said in an interview.

"We could work for absolutely nothing and we couldn't improve the market conditions that are taking place as a result of the global financial crisis."

Lewenza said he expects the same sort of concessions will be demanded from the CAW, but the union has yet to decide what it is willing to give up.

"Our interest is in our members and investment in our plants and we won't put ourselves in a position where we lose investment as a result of labour costs," he said.

Lewenza acknowledged that, no matter what concessions are demanded, the next few months are going to be "shocking" and "incredibly painful" for auto workers.

The Canadian industry has already lost thousands of auto assembly and parts jobs in Ontario as plants close and production is cut. Thousands more jobs could be on the line as GM, Ford and Chrysler pare back their North American operations to deal with a big drop in sales.

The three companies operate seven assembly plants, from Oshawa to Windsor, as well as parts factories, in southern Ontario, and have a combined workforce of about 35,000 people.

"The reality is that the companies are going to restructure, and if they restructure based on the existing capacity, then there's going to be significant more job losses," he said.

"This is going to be a painful few months for auto workers on both sides of the border."

Auto industry analyst Dennis DesRosiers said the UAW will likely have to accept wage and benefit cuts of $10 to $15 an hour, in addition to the $20 an hour the U.S. union already surrendered in a new contract.

"So in Canada to be competitive (the CAW) has to find about $15 an hour on the low side and possibly as much as $25 an hour to be competitive to the new Bush administration compensation requirements," DesRosiers estimated.

"If the CAW doesn't move, then bye-bye to eventually all the Detroit Three assembly plants in Canada."

The CAW has already accepted a three-year wage freeze in their latest contract, a concession the union says amounts to $900 million in savings for the carmakers over the lifetime of the deal, which expires in 2011.

Even with an aid package, some analysts predict the Canadian vehicle assembly and parts sector will lose between 15,000 and 20,000 jobs as GM and Chrysler restructure and streamline operations.

Lewenza said the money promised by the Bush administration is enough to get General Motors and Chrysler through the first quarter of 2009, but the industry still needs "some long-term stability."

The industry has been battered by a major slump in U.S. demand, an increasingly dark economic outlook and tight credit markets.

One U.S. official said $13.4 billion of the Bush administration money would be available this month and next -- $9.4 billion for General Motors Corp. and $4 billion for Chrysler LLC. Both companies have said they soon might be unable to pay their bills without federal help. Ford Motor Co. has said it does not need immediate aid.

Bush said his package demands concessions similar to those outlined in a bailout plan approved by the U.S. House of Representatives but rejected by the Senate a week ago. It would give the automakers three months to come up with restructuring plans.