Jo Ann Ross, a longtime Paramount Global and CBS senior advertising executive, is transitioning to a new advisory role as chairman of Paramount Advertising.

Ross, who is president and chief advertising revenue officer of U.S. advertising sales for Paramount Global, will be replaced by John Halley, a longtime Paramount Global and Viacom advertising executive.

Halley will have the title of president of Paramount Advertising, leading all the company’s national linear and streaming advertising business.

Ross, a 30-year advertising veteran at the company, first came to the CBS Television Network in 1992 as vice president of Olympics sales. She was promoted through the years at the network and then at ViacomCBS, and more recently was head of advertising at Paramount Global.

She became the first woman to be appointed head of advertising at a broadcast network and the longest-serving advertising sales senior executive in TV. Ross has been instrumental in creating new approaches to selling traditional network TV through the years and in the wake of new digital video and streaming business.

Halley has been executive vice president and chief operating officer, advertising for Paramount Global. He came to Viacom in 2007, leading commercial and business operations in a number of roles at Viacom, ViacomCBS and then Paramount Global.

Halley has led many product introductions at the company, including Viacom Vantage, the audience-targeting platform; EyeQ, Paramount’s connected TV ad product; and the creation of OpenAP, the advanced advertising platform. He currently serves as chairman of OpenAP.