Elon Musk, Tesla CEO and Twitter's biggest shareholder, has decided not to join the social media company's board, Chief Executive Parag Agrawal said in a tweet on Sunday. 

Musk, who disclosed a 9.2-percent stake in Twitter just a few days ago, was offered a board seat and his appointment was to become effective on Saturday. 

But "Elon shared that same morning that he will no longer be joining the board," Agrawal said in a tweet.

Musk had on Saturday suggested changes to Twitter Blue premium subscription service, including slashing its price, banning advertising and giving an option to pay in the cryptocurrency dogecoin.