The Akamai Board of Directors announced Monday that Dr. Tom Leighton will succeed Paul Sagan as CEO of Akamai effective January 1, 2013. Sagan announced earlier this year that he intended to step down as chief executive by the end of 2013. Leighton and Sagan will remain Akamai directors, and Sagan will become a senior advisor to the company, working with the new CEO on business strategy and to ensure a smooth management transition.