NEW YORK - General Motors Co., the automaker 61 percent owned by the U.S. government, is seeking to raise $12 billion to $16 billion in an initial public offering, a person familiar with the plan told Bloomberg.

The more than 500-page document, called an S-1, is expected to be filed Friday, though it may not happen until Monday, said the person, who asked not to be named because the discussions are private. The exact value of the offering may not be fully detailed in the registration statement filed with the U.S. Securities and Exchange Commission, said the person.

The IPO would be the second-largest in U.S. history, behind Visa Inc.'s $19.7 billion initial offering in March 2008. The share sale is also the first step in freeing the Detroit-based automaker from government ownership, which CEO Ed Whitacre has pushed for after GM's $50 billion taxpayer bailout in the wake of its bankruptcy in June 2009.

“After the restructuring, I expect GM to once again be a leading company on the U.S. stock market,” said Kim Yong Tae, who helps manage $2.9 billion equivalent of assets at Yurie Asset Management Co. in Seoul. “The U.S. government has shown a strong will to revive GM. It's a stock I want to add to my portfolio.”

GM has secured a $5 billion revolving line of credit from a group of at least 15 banks as of Wednesday night New York time, said the person. More than half are named in the draft of the document as underwriters, including Morgan Stanley, JPMorgan Chase & Co., Citigroup Inc., Bank of America Corp. and Credit Suisse Group AG.

Selim Bingol, a GM spokesman, declined to comment on details of the IPO.

“We will do an IPO when conditions are right for the company and in the markets,” he said in an e-mail.

Most of the shares offered would come from the U.S. Treasury, the person said. The aim is to sell a fifth of the government's 304 million shares, two people familiar with the plan said in June. That would reduce the Treasury's holdings to less than 50 percent.

The automaker may sell a small number of new shares, the person familiar with the plans said yesterday. The Canadian government, the United Auto Workers union's retiree medical trust and the estate of the bankrupt predecessor General Motors Corp. haven't decided whether to participate in the IPO, the person said.

The document will describe the old GM, its restructuring in bankruptcy and liabilities facing the new company, the person said.

GM will report its second quarter profit today, and industry analysts are looking for strong results to set the stage for the IPO even as consumer confidence wanes.