Sean Moran, a veteran of Viacom’s ad sales efforts for two decades, will now oversee them.

Viacom said Wednesday that Moran, who had most recently been executive vice president of national brand sales, would now serve as head of marketing and partner solutions. He replaces Jeff Lucas, who will join Snapchat,  the instant-messaging social-media application that struck a partnership with Viacom earlier this year, as its vice president of sales.

Moran will report to Tom Dooley, Viacom’s chief operating officer. “Sean is the right leader to guide this group to new heights,” Dooley said in a statement. “He has been a standout performer with Viacom and his knowledge of our business and the advertising marketplace is unsurpassed.”

Moran will take the reins at a chaotic time for the company, which operates MTV, Nickelodeon and Comedy Central, among others. The company is in the midst of a bruising boardroom battle between its controlling shareholders, Sumner Redstone and Shari Redstone, and its current leadership.

Viacom has suffered from ratings declines in recent years as its young audiences adopt new types of video-viewing behaviors. With that dynamic at play, the company has worked to create new alliances with advertisers that rely on audience targeting and consumer data. The company has also created new services for clients, including creating so-called “branded content” as well as helping advertisers get more traction on social media.

Moran will supervise ad sales for everything except BET, which has long run a separate advertising outreach from the rest of the company. But he will oversee advertising on MTV, VH1, Comedy Central, Spike, Logo, Nickelodeon, TV Land, and CMT. He has been executive vice president of national ad sales for all MTV brands as well as senior vice president of national ad sales at VH1  He began his ad sales career in the sports division of Time Warner’s Turner. Before entering the world of advertising, Moran played professional basketball in Europe.

Moran will supervise a team of senior ad-sales executives that includes Jim Balbirer, Elizabeth Herbst-Brady, John Halley, Neil Holt, Jim Perry, and Mike Tedone, along with Niels Schuurmans and Dario Spina who run Viacom’s in-house Velocity agency, which creates content for clients.