Elon Musk's twitter account is seen on a smartphone in front of the Twitter logo in this photo illustration taken, on April 15, 2022. Reuters

Billionaire Elon Musk has reached an agreement to acquire Twitter for approximately $44 billion, the company said.

The outspoken Tesla CEO, the world’s wealthiest person, has said he wants to buy Twitter because he thinks it’s not living up to its potential as a platform for "free speech.”

He says it needs to be transformed as a private company in order to build trust with users and do better at serving what he calls the "societal imperative” of free speech.

Twitter confirmed it is selling the platform to billionaire entrepreneur Elon Musk in a deal valued at $44 billion.

Musk describes himself as a "free-speech absolutist,” although he hasn’t been exactly clear what he means by that. In a recent TED interview, the billionaire said he’d like to see Twitter err on the side of allowing speech instead of moderating it. He said he’d be "very reluctant” to delete tweets and would generally be cautious about permanent bans. He also acknowledged that Twitter would have to abide by national laws governing speech in markets around the world.

Musk himself, though, regularly blocks social media users who have criticized him or his company and has used the platform to bully reporters who have written critical articles about him or his company.

Twitter’s board at first enacted an anti-takeover measure known as a poison pill that could have made a takeover attempt prohibitively expensive. But when Musk outlined the financial commitments he’d lined up to back his offer of $46.5 billion - and no other bidders emerged - the board opened negotiations with him.

Twitter and Musk spoke Sunday and into the early hours Monday, The New York Times reported, less than two weeks after the billionaire first revealed a 9 percent stake in the platform that he uses to promote his interests, attack critics and opine on social and economic issues to his more than 83 million followers.

Musk said last week that he had lined up $46.5 billion in financing to buy Twitter, putting pressure on the company’s board to negotiate a deal. Musk hasn't commented on the negotiations but on Monday waded into the buzz about them on Twitter, where some users are promising to quit the platform if he takes over.

"I hope that even my worst critics remain on Twitter, because that is what free speech means,” he tweeted.

Musk has described himself as a "free-speech absolutist” but is also known for blocking or disparaging other Twitter users who question or disagree with him.

In recent weeks, he has voiced a number of proposed changes for the company, from relaxing its content restrictions - such as the rules that suspended former President Donald Trump’s account - to ridding the platform of fake and automated accounts, and shifting away from its advertising-based revenue model.

Twitter’s board has flexibility in judging Musk’s proposal not just on the finances but also the specifics of his business plan and how it could affect users, advertisers and employees - some of whom might leave, said Kevin Kaiser, a finance professor at the Wharton School at the University of Pennsylvania.

"What’s critical for the board is whether they think it’s in the best interest of the company,” Kaiser said. "That can come from many, many factors.”

Kaiser said the board could decide that Musk’s plan has "too many negative impacts,” but that would be a hard case to make given how much Musk is offering to pay.

Asked during a recent TED talk if there are any limits to his notion of "free speech,” Musk said Twitter or any forum is "obviously bound by the laws of the country that it operates in. So obviously there are some limitations on free speech in the US, and, of course, Twitter would have to abide by those rules.”

Beyond that, though, he said he’d be "very reluctant” to delete things and in general be cautious about permanent bans.

It won’t be perfect, Musk added, "but I think we want it to really have the perception and reality that speech is as free as reasonably possible."

Agencies