TORONTO - The Ontario government won't rush to sell its stake in General Motors once the company's shares begin trading publicly again, waiting instead for when it's most profitable.

"I think we need to be patient and we need to be businesslike in terms of understanding when the time is going to be appropriate," Premier Dalton McGuinty said Friday.

This means the provincial government won't follow the lead of Washington, which said Thursday it intends to sell some of its 61 per cent stake in GM when the automaker conducts its initial public stock offering, which could happen as early as October.

The U.S., Canadian and Ontario governments all own portions of GM after lending the company billions of dollars to help it survive a massive restructuring last year.

The Ontario government took a four per cent stake in the troubled automaker while the federal government took another eight per cent after they together lent it $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.

On Thursday, the U.S. Treasury provided guidance on how it intends to be involved in GM's much-anticipated stock sale, which is expected to be among the largest initial public offerings in U.S. history.

"GM must determine that it is, in all relevant respects, ready to become a public company. For those reasons, it is critical that the process of preparing for a potential IPO be managed by GM," the department said.

Treasury said GM will choose the banks that underwrite the deal, "subject to Treasury's agreement that the selection is reasonable," but the department will determine the fees to be paid to the banks. Major Wall Street banks are trying to become the lead underwriter of the stock sale but the government is expected to push for low fees.

Ontario government spokesman Tim Weber said Canada will use its one seat on GM's board of directors to weigh in on the details of the IPO. The two governments appointed Carol Stephenson, dean of the University of Western Ontario's business school, to represent their interests on the board.

GM has said it may sell shares in late 2010 or early 2011. But CEO Ed Whitacre and company officials have said the timing will be determined by the state of the financial markets, the overall health of the auto industry and GM's ability to make progress.

To pay off its shareholders -- including the three governments, a United Auto Workers union health-care trust and its old bondholders -- the stock market would have to value GM at more than US$70 billion. That would be nearly double Ford Motor Co.'s market value of more than $38 billion, but far less than the total value of Toyota's shares of more than $110 billion.