Trading in shares of Google could begin tomorrow after the firm asked US regulators to rubber-stamp its registration.

Approval from the Securities and Exchange Commission (SEC) would enable Google to close the auction that is determining its share price.

In a statement posted on its website, Google asked that the registration be made effective at 8pm GMT today and added that successful bids could be accepted within an hour.

Google is planning to sell 26 million shares on the tech-heavy Nasdaq stock market, raising around 3 billion US dollars (£1.63 billion).

This would place its market value below that of rival Yahoo - but higher than fast food giant McDonald's and electronics group Sony.

Google unveiled plans to float in April and surprised the market by opting to sell its shares via a Dutch auction, which gives individual investors a better chance of acquiring a stake in the company.

The price is determined by the investors themselves, who state how much they are willing to pay for each share.

The highest bidders are guaranteed a stake in the company and the issue price is set by the lowest bid after all shares are allocated.

But the process has not been smooth and recent turbulence on the stock market led to speculation on Wall Street that Google may delay its listing.

The company also revealed yesterday that the SEC has opened an informal inquiry into its failure to properly register the shares issued to employees and contractors.

It followed Google's admission that it neglected to register 23 million shares and 5.6 million options issued between September 2001 and July 2004.

The inquiry could lead to Google being fined by the SEC if it is found to have breached federal or state laws.

Google was developed by students Larry Page and Sergey Brin from their dorm room at Stanford University, California, and now conducts more than 200 million searches a day.

Its technology is licensed to more than 100 companies and Google also has a news site and shopping service known as Froogle. Annual sales reached 961.9 million US dollars (£522.6 million) and the company employed 1,678 staff at the end of last year. ends