The sale amounts to 42% of Schmidt's 7.6 million Class A and Class B shares in the company, a 2.3% stake in the company, but 8.2% of voting power.
The sale is part of a pre-arranged trading plan for Schmidt's "long-term strategy for individual asset diversification and liquidity," according to the filing.
"Using this trading plan, Eric can diversify his investment portfolio and can spread stock trades out over a period of one year to reduce market impact."
Google's share price climbed 1.5% yesterday to a new all-time record of $785.37, putting the value of the shares Schmidt will sell at $2.51 billion.
In its September 2012 billionaires list -- when Google shares crossed the $700 line for the first time -- Forbes ranked Schmidt 138th in the world, with his fortune worth $7.5 billion.