Elon Musk offered to buy the rest of Twitter Inc. in a deal valuing the social-media platform at more than $43 billion, saying he wants to take the company private to make it the online home for free speech.
Mr. Musk called the bid his “best and final offer,” adding that if his proposal isn’t accepted “I would need to reconsider my position as a shareholder.” Mr. Musk earlier this year built a position of more than 9% in Twitter.