New York (CNN Business) Hedge fund Elliott Management Corp. has obtained a large stake in Twitter and is advocating for changes, including possibly replacing CEO Jack Dorsey, a source familiar with the matter confirmed to CNN Business.

Bloomberg was the first to report the news, which was then confirmed by Reuters

Elliott has nominated four directors to Twitter's board in an attempt to fill three vacant seats at this year's annual meeting, according to sources.

Twitter TWTR The New York-based firm, founded by billionaire Paul Singer, is also having "constructive discussions" with, the source said. Twitter and Elliott Management declined to comment.

It's not clear how big a stake Elliott has in Twitter or who it wants to replace Dorsey with, Reuters and Bloomberg reported.

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