Google closed its unusual auction to set its initial stock price Wednesday as it received regulatory approval for its IPO hours after dramatically lowering estimates and cutting the size of its offering.

The Internet search giant did not immediately disclose how much it will cost winning investors to purchase shares of the company.

Despite reducing the number of shares to be sold to 19.6 million from 25.7 million and cutting its estimated price range by nearly a third to $85 to $95 a share, the offering is one of the biggest and highly anticipated for an Internet company.

Before trading begins, the company and its underwriters must announce the share price of the initial sale. The earliest that could happen is 5 p.m. ET, said a source familiar with the situation. After that, winning bidders will be notified and shares will be allocated.

Investors who bid above the selling price will only pay the per-share IPO price. If there's demand for more than the company's 19.6 million shares, successful bidders may get just a percentage of what they requested.

Once the price is set and initial shares sold, the stock could begin trading, possibly as early as Thursday morning, under the symbol "GOOG" on the Nasdaq Stock Market.

Google anticipates its shares will be priced between $85 and $95 each, down from an earlier estimate of between $108 and $135. It could raise $1.86 billion. If the IPO prices at the high end of that range, the company would have a market capitalization of about $25.8 billion, down from the earlier figures as high as $36 billion.

The bumpy IPO process has created several clouds over the company that has been criticized for being too idealistic, arrogant and reckless since it began the IPO process four months ago.

Its prospectus indicates that Google still faces regulatory questions. In one case, it said the SEC "has requested additional information concerning the publication" of an interview of Google founders Sergey Brin and Larry Page that appeared in September's issue of Playboy magazine. That was a potential violation of the SEC's rules against talking publicly before an IPO about information that is not included in the prospectus.

Google also has admitted that the agency has launched an informal inquiry into its issuance of millions of pre-IPO shares and options without registering them.

The auction �� another source of controversy �� was supposed to democratize the IPO process, which is usually limited to investors connected to investment banks. Still, many analysts questioned whether Google's projected price was affordable to average investors.

Google, until Wednesday, surprised many by bucking the market trends for so long. In fact, it's repeatedly been a source of surprises since it announced its public stock offering in April.

Source: Agencies