Vivendi SA, the media and telecommunications company that ousted its chief executive this week, plans to seek a buyer for its $8.1 billion stake in Activision Blizzard Inc., a person with knowledge of the situation said.

Should no buyer emerge for the 61 percent holding in the Santa Monica, Calif.-based video-game publisher, Paris-based Vivendi plans to sell a partial stake on the open market, said the person, who declined to be named because the plans are private.

Vivendi Chairman Jean-René Fourtou is under pressure from investors to restructure the company and boost the stock price from a near nine-year low. Activision, maker of the “World of Warcraft” and “Call of Duty” titles, is among the easiest assets to sell since it is traded publicly.