European Competition Commissioner Margrethe Vestager does not care who owns Twitter as long as they obey the rules, she told German newspaper DieZeit today.

"Things would only get problematic if Elon Musk were to buy several social networks," the newspaper quoted Vestager as saying.

Earlier this week Twitter said it was selling the platform to billionaire entrepreneur Elon Musk in a deal valued at $44 billion.

The sale was a dramatic shift for the board, which had originally maneuvered to block Mr Musk from taking the social media network private.

"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 joint release announcing the takeover.

He had taken a major stake in the firm earlier this month before lining up last week some $46.5 billion in financing to push forward with the purchase.

The deal will shift control of the social media platform populated by millions of users and global leaders to the world's richest person.