Elon Musk clinched a deal to buy Twitter Inc for $44 billion cash on Monday in a transaction that will shift control of the social media platform populated by millions of users and global leaders to the world's richest person.
It is a seminal moment for the 16-year-old company that emerged as one of the world's most influential public squares and now faces a string of challenges.
Discussions over the deal, which last week appeared uncertain, accelerated over the weekend after Mr Musk wooed Twitter shareholders with financing details of his offer.
Under pressure, Twitter started negotiating with Mr Musk to buy the company at the proposed $54.20 per share price.
"Free speech is the bedrock of a functioning democracy, and Twitter is the digital town square where matters vital to the future of humanity are debated," Mr Musk said in a statement.
Twitter's shares were up about 6 per cent following the news.