Google executive chairman Eric Schmidt plans to sell 42 percent of his shares in the company, as revealed in an SEC filing on Friday. The former CEO currently owns about 2.3 percent of the search giant, but plans to sell about 3.2 million of his 7.6 million shares. Based on the current value of Google's stock, that's worth a cool $2.51 billion. Schmidt has the option to spread the sale of the shares out over the course of a year to reduce the impact it will have on the market.

This isn't the first time that Schmidt has dumped shares — last February he offloaded $1.5 billion worth. While Schmidt was CEO of the company, he was paid only $1 per year, so his compensation came in the form of stock. But once he stepped down from CEO and accepted his position as executive chairman, Google upped his annual salary to $1.25 million. Back when he was on the board of Apple, Schmidt did not receive any salary or stock as compensation for his term there (though he reportedly received some Apple gear and a commemorative gift worth a few thousand dollars). As of last September, Forbes estimated Schmidt's net worth to be $7.5 billion. Even after today's big sale, the chairman still owns enough stock to make him a billionaire numerous times over, if he decided to cash out completely, of course.