The total offering size will be $20.1 billion

The total offering size will be $20.1 billion Shares of General Motors Co., a company that seemed headed for the scrap heap last year, are poised to roar out of the gate Thursday, shattering records for billion-dollar stock offerings and putting the refurbished automaker back in the driver’s seat.

GM will sell 478 million shares at $33 (U.S.) in its initial public offering, or IPO, the company said in a release Wednesday. It will also sell 87 million shares of mandatory convertible junior preferred stock for a total of $4.35 billion.

The total offering size will be $20.1 billion (U.S.), but it could reach $23.1 billion if the investment banks underwriting the deal opt to purchase additional shares in the next month, the Detroit-based manufacturing giant said.