By Peter Whoriskey; The Washington Post ~ Sep 17, 2010

When the U.S. Treasury begins selling off its stake in General Motors, it will not seek to allocate shares to specific buyers, but officials expect that no single investor or group of investors will receive "a disproportionate share," the department said today.

The guidelines for the sale, filed by the department this evening, appear to address concerns that a foreign company could buy up a majority of the automaker's shares.

The United States owns about 61 percent of General Motors after spending $50 billion to bail out the company. The U.S. government is now preparing to sell off those holdings.

"We expect that potential investors will be sought across multiple geographies with a focus on North American investors," the guidelines state.

As long as its guidelines are followed, the Treasury "will not involve itself in decisions regarding allocation of shares to specific buyers," and instead will leave the details of the sale up to GM and the underwriters of the sale.

The guidelines also address suggestions that the Treasury seek to sell its GM shares mainly to retail U.S. investors, rather than the large institutional investors such as mutual funds, hedge funds and pensions that typically buy up large stakes in public offerings.

"We expect that a large and diverse group of institutional investors will be offered an opportunity to participate," the guidelines published Friday say. "We expect that interested retail purchasers will be given ample opportunity to participate."

Including institutional investors will help the U.S. government gain a higher share price, and thus a larger return on its investment.

By Peter Whoriskey  |  September 17, 2010; 5:59 PM ET