Viacom said that CEO Philippe Dauman has been elected executive chairman of the company, succeeding Sumner Redstone, who becomes chairman emeritus.
Redstone on Wednesday stepped down as chairman of CBS, succeeded by CEO Les Moonves.
The moves are a step toward succession at the media companies controlled by Redstone, who at 92, is in poor health and being questioned about his ability to make healthcare and financial decisions.
Viacom's board offered the chairman's post to Sumner Redstone's daughter Shari Redstone, but she turned it down and will continue as non-executive vice chairman.
On Wednesday, Shari Redstone said she supported the election of Moonves as chairman of CBS, but wanted a more independent chairman at Viacom.
After the board meeting and Dauman's election was annnounced, a statement was released on behalf of Shari Redstone that said: "Shari is going to continue to advocate for what she believes to be in the best interests of Viacom shareholders."
Viacom has been performing poorly as its cable networks have suffered from the defection of young viewers from traditional TV to digital entertainment options. Its stock has also suffered, falling more than 40% last year.
"In choosing a successor to Sumner," said William Schwartz, a lawyer and chairman of the governance and nominating committee of Viacom's board, "the Board considered the need for seasoned leadership in this time of unprecedented change, Philippe's business experience and unparalleled knowledge of Viacom, and his long-term vision for the Company. We believe his becoming Executive Chairman is in the best interests of the company and all shareholders."
Schwartz added that Dauman "has been instrumental with Sumner in every aspect of Viacom's success for nearly 30 years and most recently as CEO has taken on the tough task of navigating our future in a time of unprecedented innovation and disruption. He has laid out a strategic long-term vision for the company that we fully endorse. We have complete confidence that his dedication to Viacom, his global experience and his determination to further our culture of creativity and innovation will continue to serve the interests of all shareholders and build long-term value."
Dauman was named president and CEO of Viacom in 2006.
"I am honored to succeed my friend and long-time colleague Sumner in the role of Executive Chairman," Dauman said. "His steadfast belief in our company and the power of entertainment will always be an inspiration for me and I look forward to carrying forward his leadership role as a champion for all shareholders. I am gratified by the continued confidence and support of the Board of Directors and all of my colleagues at Viacom whose creativity and unrelenting hard work is evident in our recent successes across the Company."
"Sumner Redstone's contributions to Viacom and the media industry are legendary," added Schwartz. "He has successfully led Viacom with a dedication to building a global business for the benefit of all shareholders. On behalf of the Viacom Board, his colleagues and all our shareholders, we want to thank Sumner for his vision and leadership. There is no one who loves this company more and we will continue to be inspired by his wisdom in the years to come."