Google is planning to sell an additional 5.3m shares. The main reason, according to the press release, is to increase the supply of shares available in the market, as the search engine will be added to the S&P 500.

What that doesn’t answer the question: why does Google need the $2.1bn that the floatation will bring?

The SEC filing doesn't give us anything either. It is using standard phrasing to say that there is nothing to say:

"We anticipate that we will use the net proceeds from this offering for general corporate purposes, including working capital and capital expenditures. In addition, we may use proceeds of this offering for acquisitions of businesses, technologies or other assets that we believe will complement our business."

Full story: siliconvalleysleuth.com