U.S. auto sales are expected to end 2009 on a slight upswing in December, capping a year that saw General Motors and Chrysler collapse into bankruptcy and China overtake the United States as the biggest car market.

The deepest U.S. economic downturn since the Great Depression hammered auto sales through most of 2009, but a poll suggests December will mark a third consecutive month of modest growth in the annualized basis favored by industry analysts.

The results would point toward a gradual recovery in U.S. auto sales in 2010, an outlook favored by most in the industry, but still leave sales rates well below figures not imagined by even the most pessimistic of analysts two years ago.

The main question: Will sales rally enough in December to make 2009 the worst year for U.S. light vehicle sales since 1982, or will they fall short, marking the worst year for U.S. auto sales since 1970?

TrueCar analyst Jesse Toprak expects 2009's U.S. auto sales to be the worst since 1970, or 1950 on a population-adjusted basis. Sales to corporate fleets or car rental companies remain a wild card and could push the total higher, he said.

U.S. light vehicle sales are expected to be down nearly 40 percent in 2009 from the most recent peak of nearly 17 million in 2005 -- and only because U.S. government "cash for clunkers" incentives boosted sales sharply in July and August.

The collapse in U.S. auto sales in 2009 coupled with surging sales in China approaching 13 million units this year, including commercial vehicles, marked a stark shift in global vehicle volumes that was much quicker than many had expected.

U.S. auto sales on average are expected to come in at an 11 million unit adjusted annualized rate in December, according to a survey of 21 analysts compiled by Reuters. Their annualized outlooks ranged from 10.4 million to 11.4 million vehicles.

That would be the strongest monthly sales result of 2009 excluding the "clunkers"-boosted results of July and August.

Barclays Capital expects the annualized sales rate to come in at just above 11 million vehicles in December.

"Excluding the cash-for-clunkers months, this would constitute the strongest sales rate since September 2008, suggesting the industry is witnessing a real improvement in underlying demand for U.S. autos which bodes well for 2010," Barclays analyst Brian Johnson said in a note on Thursday.

GRADUAL SALES RECOVERY SEEN IN 2010

Overall, Johnson said he expected GM to post one of its best market shares of the year, in part due to heavy dealer incentives aimed at selling off the last of its Pontiac and Saturn vehicles as the brands are shut down.

Ford Motor Co's (F.N) market share should be in line with the last few months, he said. Chrysler is expected to post a steep year-over-year sales decline, while Toyota Motor Corp (7203.T), Honda Motor Co Ltd (7267.T) and Nissan Motor Co Ltd (7201.T) may outperform the market, Johnson said.

J.D. Power and Associates said last week it expected the sales rate to reach 11.2 million vehicles in December. The influential forecaster expects U.S. auto sales to continue a gradual recovery to near 11.5 million vehicles in 2010.

TrueCar's Toprak expects U.S. sales of about 11.4 million vehicles in 2010 and said it could take three years or more for U.S. auto sales to return to the 14 million range. He believes most domestic automakers could be profitable on industry sales of 11.5 million per year after their massive restructurings.

Edmunds expects sales to be up 13.3 percent in December from a year ago, or 5.2 percent when adjusting for two extra selling days this year versus last December.

The year cannot end soon enough for automakers. The GM (GM.UL) and Chrysler bankruptcies left GM held 60 percent by the U.S. Treasury and Chrysler under the management control of Italy's Fiat SpA (FIA.MI). They top the list of auto industry distress in 2009, but those automakers were far from alone.

Toyota's U.S. sales had plunged nearly 24 percent through November and it faces its largest-ever recall to fix the accelerator pedals on nearly 4 million vehicles after reports of sudden bursts of acceleration that led to deadly crashes.

Ford, the only large U.S. automaker not to restructure in bankruptcy in 2009, expanded a recall involving faulty cruise control switches that have caused fires. Ford also must address a much higher debt load than its U.S. rivals.

The long-expected acquisitions of U.S. auto assets by China-based companies took a big step forward in 2009 as well, with Ford nearing agreement to sell its Swedish brand Volvo to Zhejiang Geely Holding Group, parent of Geely Auto.

GM as well has reached an agreement to sell some of its Saab brand assets to Beijing Automotive Industry Holding Corp, or BAIC. GM was still considering potential offers for Saab, while continuing the process of shutting down the brand as part of its global restructuring if no deal can be reached.