Moritz, a partner with Sequoia Capital, gained notoriety as one of the early investors in Yahoo. According to Yahoo, Moritz resigned because of a desire to spend more time with his investment companies. Activision CEO Robert Kotick replaced Moritz, who was not immediately available for comment.
Sequoia invested in Yahoo in 1995, funding the two-man operation that consisted of founders Jerry Yang and David Filo. Sequoia went on to see its original investment foster the creation of a company with a market value of $100 billion, based on a spit-adjusted price of $237.50 a share, in January 2000.
"Since its inception, Yahoo has benefited greatly from Mike's many outstanding and important contributions," Yang said in a statement. "He has played a critical role in the company's continued success, and we are deeply grateful for his leadership and friendship."
Moritz also serves as a director for such companies as Google, Saba Software and Flextronics International.
Kotick, 40, has been in the video-game industry for more than a decade. He initially took a controlling stake in Activision in 1990, and then became chairman and chief executive the next year.
"Bobby's strong entrepreneurial background, along with his expertise in creating a broad range of compelling products and marketing them directly to consumers around the world will be an important asset to Yahoo," Terry Semel, Yahoo chief executive, said in a statement.
Kotick is the latest director to join Yahoo's board, sincein April 2001. In November, 2001, Ron Burkle, founder of The Yucaipa Companies, and Gary Wilson, chairman of Northwest Airlines and former Walt Disney chief financial officer, to its board.