Elon Musk says he will serve as chief executive officer of Twitter.
Musk, who also runs electric vehicle manufacturer Tesla, rocket company SpaceX, brain-chip startup Neuralink and tunneling firm the Boring Company, fired Twitter's previous chief Parag Agrawal and other top company officials last week after his $44-billion acquisition.
Musk has also proposed revisions to the platform's user verification or "blue tick" process, which has been free until now.
Responding to a tweet from author Stephen King that he would not be willing to pay US$20 a month to keep the verified badge on Twitter, Musk replied: "How about $8?"
The billionaire said introducing a price was the only way to defeat trolls and bots on the platform and that Twitter could not entirely rely on advertisers to pay its bills.
Tesla's stock has lost a third of its value since Musk made an offer to buy Twitter in April, compared with a 12 per cent decline in the benchmark S&P 500 index in the same period.