Elon Musk took a swipe at the board of Twitter on Monday after the social media company adopted a "poison pill" to protect itself from the second-biggest shareholder's $43 billion cash buyout offer.

    "Board salary will be $0 if my bid succeeds, so that's ~$3M/year saved right there," Musk tweeted in response to a user's post criticizing the board.

    Later, the Tesla (TSLA.O) chief executive also tweeted "Love Me Tender", an Elvis Presley song, after Twitter opted a plan to sell shares at a discount to prevent any attempt by shareholders to amass a stake of more than 15%. Musk currently has a 9.1% stake.

    Dorsey's statement was a reply to a tweet by venture capitalist Garry Tan that said: "The wrong partner on your board can literally make a billion dollars in value evaporate."

Shares of Twitter were up about 4% at $46.85, still significantly below Musk's offer of $54.20 per share. They have risen roughly 15% since Musk disclosed his stake on April 4.

    Meanwhile, Twitter has also been informed by Thoma Bravo, a technology-focused private equity firm that had more than $103 billion in assets under management as of the end of December, that it was exploring the possibility of putting together a bid.

    A Thoma Bravo spokesperson declined to comment while Twitter representatives did not immediately respond to a request for comment.

    The New York Post reported on Thursday that Thoma Bravo was considering a bid for Twitter.