CALIFORNIA, RAW – Twitter 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 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 per cent of Twitter’s common stock.

“I believe this is for the best,” Agrawal said in the note late on Sunday. “There will be distractions ahead, but our goals and priorities remain unchanged.”

The announcement was so abrupt that Musk was still listed on Twitter’s board of directors on its website as of early Monday.

Musk, whose net worth is pegged at $US274 billion ($A370 billion) by Forbes, responded only with a face-with-hand-over-mouth emoticon on Twitter.

Musk, who calls himself a free-speech absolutist and has been critical of Twitter, disclosed a 9.1 per cent stake on April 4 and said he planned to bring about significant improvements at the social media platform.

The disclosure of the stake stoked widespread speculation on his intentions, ranging from a full takeover of the platform to taking an active role in corporate decisions.

News of Musk taking a board seat had some Twitter employees panicking over the future of the social media firm’s ability to moderate content, company sources told Reuters.

Musk, a prolific user of Twitter, has made announcements about his company and a variety of issues to his more than 80 million followers on the social media platform.

Before taking a stake, Musk ran a Twitter poll asking users if they believed Twitter adheres to the principle of free speech.

A day after becoming the largest shareholder, he launched another poll asking users if they wanted an edit button, a long-awaited feature being developed by Twitter.

The Tesla boss also asked users in a poll if Twitter’s headquarters should be converted into a homeless shelter, a plan backed by Amazon founder Jeff Bezos.

On Saturday, Musk suggested changes to the Twitter Blue premium subscription service, including slashing its price, banning advertising and giving an option to pay in the cryptocurrency dogecoin.

Twitter shares, which soared 27 per cent on April 4 after Musk disclosed his stake, have lost 7.5 per cent since then to Friday’s close.