According to the Wall Street Journal, the company contacted more than a dozen investment banks earlier this month about possibly selling shares to the public, people familiar with the talks said.

Google executives trimmed the list to about half a dozen and spent two days last week interviewing representatives of those companies, the sources added.

People familiar with the talks said investment bankers had estimated Google's value at 15-25 billion dollars -- on a par with Amazon.com Inc and slightly less than rival search directory Yahoo Inc.

But some of the basic questions about a potential IPO remain unanswered, including the timing of the offering, which banks will be involved, how many shares will be offered, and even the method for distributing shares, the Journal said.

Meanwhile, the Financial Times said the IPO could be held early next year, in the form of an online auction.

That procedure would be designed to prevent a recurrence of the sort of financial scandals that have engulfed Wall Street since the collapse of the dotcom bubble, a person close to the company said.

It could also slash the underwriting fees paid to investment banks, and in the process help to break Wall Street's hold on the lucrative IPO business.

Though the privately held Google does not disclose financial information, its profits are growing rapidly and are reckoned to be running at an annual rate of about 150 million dollars on revenues of 500 million, the FT added.

SPACE.WIRE