Mark Zuckerberg is planning to sell 35-75 million Facebook shares in next 18 months

Mark Zuckerberg.[/caption]"Over the past year and a half, Facebook's business has performed well and the value of our stock has grown to the point that I can fully fund our philanthropy and retain voting control of Facebook for 20 years or more," Zuckerberg wrote in a post."I want to be clear: this doesn't change Priscilla and my plans to give away 99 percent of our Facebook shares during our lives. I anticipate selling 35-75 million Facebook shares in the next 18 months to fund our work."He said his wife Priscilla and he feel a responsibility to do their part to address global challenges — like curing all diseases in their children's lifetime and personalising education for every student.He also asked the company's board to withdraw the proposal to reclassify the stock that he proposed to create last year.The idea of the proposal was that it would allow Zuckerberg to keep voting control of Facebook so the company can continue to build for the long term and allow Priscilla and him to fund the work the were doing through the Chan Zuckerberg Initiative.