Eric Schmidt is stepping down as Google chief executive officer to take on a more external role as executive chairman, but he won't exactly be hurting for cash.

According to a Wednesday filing with the Securities and Exchange Commission, Schmidt will sell 534,000 shares of Google common stock, a move worth approximately $334 million.

The sale is detailed in a stock plan that Schmidt adopted on December 9, and is "part of his long-term strategy for individual asset diversification and liquidity," the filing said.

"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," the filing continued. "Because this trading plan was established well in advance of a trade, it also helps avoid concerns about whether Eric had material, non-public information when he made a decision to sell his stock."

As of December 31, Schmidt owned 9.2 million shares of common stock, which is 2.9 percent of Google's outstanding capital stock and 9.6 percent of the voting power of Google's outstanding capital stock. Selling the 534,000 shares won't have a major impact on those percentages; they will drop to 2.7 percent and 9.1 percent, respectively.

In his new role, Schmidt will "focus wherever I can add the greatest value: externally, on the deals, partnerships, customers and broader business relationships, government outreach and technology thought leadership that are increasingly important given Google's global reach; and internally as an advisor to Larry and Sergey," he said.

"A decade is a long time to be a CEO," Schmidt said during Google's fourth quarter earnings call.

Larry Page will become Google CEO effective April 4 and Sergey Brin will be co-founder.

For more, see PCMag's take on How Larry Page Will Lead Google.

See why Editor Lance Ulanoff thinks Schmidt's CEO exit marks the end of an era.