General Motors Co. will trade its shares on the main market in Canada as well as in the United States, the company said as it took the first step needed to sell its stock to the public and liberate itself from the moniker of "Government Motors."

"We intend to apply to have our common stock listed on the New York Stock Exchange and the Toronto Stock Exchange," the company said in its registration statement, filed with the U.S. Securities and Exchange Commission on Wednesday.

The 700-page registration form begins a process that will lead to an initial public offering of GM's stock. No date was set for the sale, but experts say the IPO could come as early as October.

Stakeholders in the company, which include the U.S., Canadian and Ontario governments, will initially sell common stock, while GM will sell preferred shares that are similar to bonds. The forms did not say how many shares would be sold or at what price.

Speculation has put the offering price of GM's shares as high as US$100, said Tony Faria, co-director of the automotive research centre at the University of Windsor.

"(This) seems astounding given that you can buy a share of Ford right now for about $13 and Ford did not go into bankruptcy," Faria said.

GM delisted its shares from the New York Stock Exchange in early 2009 when the company began a massive reorganization under Chapter 11 bankruptcy protection in the United States. As part of its restructuring, the company accepted billions of dollars in aid from the American, Canadian and Ontario governments.

In exchange, Ottawa took an eight per cent stake in the automaker and Ontario took another four per cent after they together lent it C$10.5 billion. About $9 billion of that loan was converted to equity when the so-called "new GM" emerged from bankruptcy protection, while the rest has been paid back.

The American government, meanwhile, lent GM US$50 billion in exchange for 61 per cent of the company. Of that, GM has repaid $6.7 billion, and the remaining $43.3 billion was converted to the ownership stake.

Federal Finance Minister Jim Flaherty said Ottawa hasn't yet decided when it will sell its stake in the company.

"Canada may participate in an initial public offering by General Motors, but any decision we take is with the goal of maximizing the return for taxpayers while reducing our ownership in the company as quickly as is appropriate," Flaherty said in a statement Wednesday.

He added that the IPO is a clear indication Canada "made the right decision" to support the company, and said he is "pleased" GM has decided to list on the TSX.

The Ontario government has also said it doesn't know whether it will put its stake in GM up for sale immediately.

Meanwhile, Washington has said it plans to sell some of its stake right away. Faria speculated the U.S. government will initially sell about one-quarter of its shares, or approximately 15 per cent of the company.

GM said in the filing that the U.S. government would continue to own a "substantial interest" in the automaker following the IPO.

GM's outgoing CEO, Ed Whitacre, has said the company is eager to begin selling its shares publicly so it can end its dependence on the government. Whitacre wants the company to shed its "Government Motors" moniker because it's hurting sales and the company's image.

GM announced last week that Whitacre will step down as CEO on Sept. 1 and be replaced by board member Daniel Akerson.

A GM IPO could be the largest in U.S. history. It would have to bring in US$70 billion to pay back all of GM's stakeholders. That would be more than Ford's market value of roughly $44 billion, but less than Toyota's total market value of about $113 billion. The largest U.S. IPO so far is Visa Inc.'s 2008 offering that raised $19.7 billion.

The company said it will trade on the New York Stock Exchange under the ticker "GM," the symbol under which it traded before it entered bankruptcy. The ticker symbol to be used in Toronto hasn't been determined.

The company gave investors a lengthy list of risks facing it on Wednesday, including restructuring costs and concerns about the competitiveness of its vehicles.

For example, the Chevrolet Volt, its highly anticipated electric car due for release this year, requires battery technology "that has not yet proven to be commercially viable," the filing says.

Even new executives were listed as risk factors. GM acknowledged that incoming CEO Daniel Akerson and chief financial officer Chris Liddell have "no outside automotive industry experience" and said it was important for the management team to "quickly adapt and excel" in their new roles.

GM added that the company was dependent upon global car and truck sales and said "there is no assurance that the global automobile market will recover in the near future or that it will not suffer a significant further downturn."

The company said it had no plans to pay dividends on its common stock and future dividends would be determined by its board of directors.

Last week, GM reported that it earned US$1.33 billion in the second quarter. This was the second straight quarterly profit for the Detroit automaker, which made $865 million in the first quarter. GM's second-quarter revenue totalled $33.2 billion, up 5.3 per cent from the first quarter on growing sales in every region except Europe.

Since the restructuring, GM has eliminated all but four of its brands and has transformed itself into a much leaner, more profitable company.

GM Canada employs about 9,000 people at its Ontario-based operations. The company operates assembly plants in Oshawa and Ingersoll and parts plants in St. Catharines and Windsor.

With files from The Associated Press.