CALIFORNIA, United States (AP)— Billionaire Elon Musk has reached an agreement to acquire Twitter for approximately $44 billion, the company said.

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 per cent 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 had said that 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.”

Twitter had initially enacted an anti-takeover measure known as a poison pill that could make a takeover attempt prohibitively expensive. But the board decided to negotiate after Musk updated his proposal last week to show he had secured financing, according to The Wall Street Journal, which was first to report the negotiations were underway.