MOUNTAIN VIEW, Calif. ( TheStreet) -- Google ( GOOG) co-founders Larry Page and Sergey Brin each intend to sell about 5 million shares of company stock under prearranged stock trading plans. The plans, adopted Nov. 30, will be part of a five-year diversification program for the executives' portfolios, according to a filing made Friday with the Securities and Exchange Commission. Executives use such plans, in which stock sales are scheduled in advance over a period of time, to reduce the market impact of the sale on company stock, and to avoid investor concerns that the sales are based on access to negative inside information. > > Bull or Bear? Vote in Our Poll The co-founders of the Internet search giant collectively hold about 57.7 million shares of Class B common stock, or about 18% of the company's outstanding equity, and about 59% of shareholder voting power. If they complete all the planned sales, they will hold approximately 47.7 million shares of common stock, representing about 15% of Google's equity, and retain 48% of the voting power. Shares of Google ended Friday down $32.97, or 5.7%, at $550.01. -- Written by a member of TheStreet.com staff.