DETROIT – General Motors has priced its common stock at $33 per share, for a total offering of $20.1 billion, or $23.1 billion if extra shares are sold to accommodate demand. With the extra shares, the common stock alone would be the largest initial public offering in U.S. history.

GM’s return to the stock market includes 478 million common shares, increased from the initial plan to sell 365 million. GM said late Wednesday it increased the number of preferred shares it was offering to 87 million because of investor interest. GM had already increased its preferred share offering Tuesday to 80 million from the previous 60 million.

An additional 15 percent of shares is expected to be sold during the allowable 30-day period because of high demand.

The “GM” trading symbol will return to the New York Stock Exchange this morning for public trading after being booted off when GM went bankrupt in June 2009. Some shares will trade on the Toronto Stock Exchange under “GMM.”

Besides GM employees, retirees and dealers, only institutions such as hedge funds, money managers and large long-term investment firms have been able to buy stock in GM’s offering. Starting today, that stock will be available to anyone.

The final price ensures the U.S. government will take a smaller loss on each share sold than it would have with the $26-$29 range GM first announced at the beginning of the month. As part of the IPO, the U.S. government will sell up to 412.3 million shares, reducing its stake in the automaker from 60.8 percent to as low as 33.3 percent, as reported Tuesday by the Detroit Free Press and other news outlets. The U.S. Treasury needs to average $43.67 per share to recoup its entire $49.5 billion investment in GM.

Taxpayers will recoup up to $13.6 billion on the IPO. After a waiting period of at least six months, the government will need to sell its remaining shares in GM at an average of roughly $50 each to break even. Along with the stock sale, it can count on $10 billion in repaid interest and loans and soon-to-be repurchased Series A preferred stock.

The UAW health care trust, which owns 17.5 percent of GM, is offering 89 million shares, plus the extra 15 percent if demand allows. The Canadian government, which owns 11.7 percent, is selling 30.5 million, plus the 15 percent over-allotment.

Bondholders currently own 10 percent of GM, but they will not receive stock until the liquidation of the old GM assets that are still in bankruptcy.

If GM sells the extra 15 percent to meet demand, the common stock alone will be worth $18.1 billion. That will edge out Visa’s IPO of $17.9 billion in March 2008 for the largest IPO in U.S. history.

The preferred shares will add up to $5 billion in value to the IPO. GM has previously said it will put proceeds from the preferred shares toward a $4 billion contribution to its U.S. hourly and salaried pension plans, along with about $2 billion worth of common shares. GM’s worldwide pensions were underfunded by $29 billion on Sept. 30.