Google Inc., the world's hottest search engine, has launched what is expected to be the world's hottest IPO.

Google filed documents with U.S. regulators Thursday to become a publicly traded company. It plans to sell as much as $2.7 billion US in stock in its initial public offering.

However, it could be months before the shares actually become available for purchase. In any event, institutional and large investors will likely get first crack at them, experts say.

The Mountainview, California-based company said it would list either on the technology-oriented Nasdaq exchange or the New York Stock Exchange.

The value of the IPO could eventually reach $20 billion US, experts have estimated.

Google has become the world's most popular search engine in the past five years.

It has also become a profitable business by linking text ads and sponsored links to peoples' search results.

In its filings, the company made a profit of $105.6 million US on revenue of $962 million US in 2003.

It reported a first-quarter profit of $64 million US this year, which is more than double the first quarter of 2003.

The company was founded in September 1998 by two Stanford University students, Larry Page and Sergey Brin.

Google became the number-one search engine through word of mouth, having spent almost no money on marketing. It is easy to use for the casual searcher, but sophisticated enough to interest professional Internet users.

Some major competitors like Yahoo! and Microsoft have taken note of Google's success and plan on competing more directly with it in searching.

Yahoo! made several strategic investments last year, such as purchasing Overture, which also links ads to search results.

Microsoft has said it wishes to build its own search engine and integrate it with the next release of its operating system which is expected in 2006.