Google (NSDQ: GOOG) just put out an SEC filing indicating that co-founders Larry Page and Sergey Brin will soon begin to sell off some of their holdings in the company, as part of a predetermined trading plan. The men intend to sell about 10 million shares in the company over the next five years, representing about 17 percent of their holdings. According to the filing, that would mean that they would control about 48 percent of Google’s voting power, down from 59 percent, effectively giving up majority control of the company, although they, of course, would continue to wield significant executive power given the amount of stock it would take to overrule them.