DETROIT (

TheStreet

) --

General Motors

is headed back to the public markets, perhaps as soon as the second half of 2010 in what could be the year's most closely watched IPO.

It's obviously too soon to say whether the company or its pricing will be attractive, but the hope exists that investors will be looking at an automaker with vastly reduced costs and debt as well as a 20% share of a recovering U.S. vehicle market. A certainty is that existing shareholders, primarily the U.S. Treasury and an employee health care trust, will be eager sellers.

Already, "a lot of work is under way" to prepare for the IPO, CEO Fritz Henderson told reporters and analysts Monday, on a conference call focused on GM's performance in the 90 days since it emerged from bankruptcy.

In GM's accounting department, he said, "people are cranking to be ready so we can get filings done by March 31." Those filings would implement fresh-start reporting, which involves determining fair market value of GM assets and liabilities. The next step would be to create a financial infrastructure for a public company by the second half of the year, he said.

Of course, "the most important thing we can have is business results," Henderson said. He cited profitability and cash flow as the two key operating measures. Additionally, "you have to understand what the market is at a certain point." That one, however, is outside GM's control.

At least GM will have an easy way to gauge the market for auto shares, simply by looking at the performance of

Ford

(F) - Get Report

. This year, Ford shares are up about 200%. While it is true that Ford was able to remake itself without the burden of government involvement, it is also true that both Ford and GM are engaged in similar exercises -- and both appear to be succeeding.

GM's plan calls for a break even on earnings before interest and taxes as long as its domestic market share is 18 % and total annual domestic vehicle sales are 10.5 million, both numbers that seem well within reach in 2010. Henderson said his biggest concern is the pace of the economic recovery, particularly in the U.S. but also in Western Europe. GM will report financial results in mid-November.

Analysts maintain their skepticism. "It's very early to talk about an IPO," says independent auto analyst Tom Libby. "GM's products are stronger, but their market share is down over two points year over year, due to four brands going away, and their marketing is unproven. The first step is to stabilize the market share."

GM market share in the third quarter was 19.7%, down from 24.7% in the same quarter a year earlier, according to Edmunds.com. The four core brands, which will be retained, accounted for more than 90% of September sales, GM said. Hummer, Pontiac, Saab and Saturn are going away, while Buick, Cadillac, Chevrolet and GMC will remain.

Chevrolet has held up the best, with a 12.3% share in the third quarter, down from 14.8% in the third quarter of 2008, Edmunds.com said. Chevrolet's share fell by 11%, while the industry as a whole fell by 10.3%. On the call, Henderson acknowledged that Chevrolet is the key to GM's market share retention expectations, partially because it will be expected to pick up buyers from defunct Pontiac. "We are reasonably happy with the traction we've got with Chevrolet," he said.

Analyst Joe Phillippi of AutoTrends Consulting said GM shares could be worth a look "if the stock is priced right, we're at the proper point in the cycle and they have a believable story."

But he said "market share is a jump ball (because) the competition is so stiff.

Clawing back market share is going to come in tenths of a percentage point, when you are able to get them," he said. "No one gives you any quarter in this business, and we're dealing with a much smaller business, looking at a market that will be 11.5 million vehicles or so next year, when it had been 15 million or 16 million for the better part of a decade."

Phillippi said the auto industry failed to take advantage of the opportunity presented by a global economic shutdown to sharply reduce capacity. "We've got some capacity coming out, but nowhere near enough," he said. "The U.S. (companies) have all done a tremendous amount of downsizing, but we still have tremendous excess capacity offshore," he said. "People added capacity far in excess of demand."

-- Written by Ted Reed in Charlotte, N.C.