Twitter Inc. says Elon Musk rejected its offer to join the social media firm’s board, a dramatic turn in a week when the billionaire became its biggest shareholder, and it warned of more drama with “distractions ahead.”

Twitter Chief Executive Parag Agrawal said in a note posted to Twitter Sunday that the company’s board held many discussions with Musk, but he did not state the reason for the Tesla CEO’s decision.

Agrawal said the planned appointment was due to become effective on Saturday, which would have prevented the world’s wealthiest person from becoming a beneficial owner of more than 14.9% of Twitter’s common stock.