Stephen B. Burke, the chief executive of NBCUniversal, plans to step down next year, capping a decade as the leader of one of the largest media conglomerates in the country, a business that includes the Universal film studios, a set of cable outlets and the broadcast network NBC, which has been the home of the Olympics for more than two decades.

Mr. Burke, 61, plans to relinquish his position when his contract expires in August, after the Tokyo Olympics, three people familiar with the plan said. They declined to be named because they were not authorized to speak on the matter. Mr. Burke could also step aside before August, two of the people said. NBCUniversal is owned by cable giant Comcast, which acquired the business in 2011.

The news was first reported by Variety.

Jeff Shell, a longtime NBCUniversal executive, is a leading candidate to replace Mr. Burke, the people said. In January, as part of an executive shuffle, Mr. Shell was put in charge of NBCUniversal’s Hollywood operations, as well as its international business and the Spanish-language network Telemundo. Mr. Shell is likely to split his time between Los Angeles, where he is based, and New York. A onetime Comcast executive, Mr. Shell has been seen since his promotion as a likely successor to Mr. Burke.

NBCUniversal declined to comment.

In a January interview, Mr. Burke said the executive moves were a way to streamline the management structure. In addition to elevating Mr. Shell, the changes put Mark Lazarus, the longtime head of the company’s sports division, in charge of the NBC broadcast network, including the news division and cable networks.