Google could add US$2.1 billion to its $8 billion cash pile, through an issue of 5.3 million new shares.

The money will be used for expenses and possible acquisitions, said Google, but the issue is also designed to meet the demand for Google shares that will be unleashed when Google is added to the S&P 500 Index at the end of trading on Friday.

Google has grown flush with cash since raising $1.7 billion in its first public offering in 2004, and another $4 billion in a share offering last September. Some of this cash has been used to make a handful of acquisitions over the past year.

In early March, Google purchased Upstartle, developer of online word processing application Writely. Earlier this year, Google bought dMarc Broadcasting Inc., a developer of a radio advertising platform, for $100 million plus additional future payments that could reach $1 billion. Google also recently purchase 3D design company SketchUp and also invested $1 billion in America Online late last year.

Google continues to lead the search market. Google handled 41 percent of searches in the US in January, up six percentage points, according to recent research offered by ComScore Networks. Yahoo took the number two spot with almost 29 percent of searches and MSN came in third with almost 14 percent, based on the ComScore report.

The new shares would bring in US$2.1 billion based on the value of Google's stock at close of trading on Wednesday.