The deal was a "foregone conclusion" and was unanimously voted for by the board, tech blog AllThingsD reported, citing sources close to the matter.
If confirmed, it will be CEO Marissa Mayer's largest deal since taking the helm of Yahoo in July 2012.
Neither Yahoo nor Tumblr responded immediately to requests for comment.
Marissa Mayer is truly trying to prove herself now!! She's playing hardball now!! Discuss or something!!!
- GLaDOS (Portal, 2007)