Yahoo billboard in San Francisco, CA

Yahoo is in talks to acquire a controlling stake in Dailymotion, one of the world's most popular online video websites, in what would be Yahoo CEO Marissa Mayer's largest deal since taking the reins in July, the Wall Street Journal reported on Tuesday.

Yahoo could purchase as much as 75 percent of Dailymotion, which is owned by French telecommunications firm France Telecom-Orange, according to the newspaper report, which cited anonymous sources.