The latest sale brings total Tesla stocks sold by Musk to about $36 billion since November last year, leaving him with a roughly 14% stake in the world's most valuable automaker, according to a Reuters calculation.

Musk unloaded 19.5 million shares between Friday and Tuesday, filings published by the U.S. Securities and Exchange Commission showed on late Tuesday.

Tesla did not immediately respond to a Reuters request for comment on the purpose of the share sale.

Analysts had widely expected Musk to sell more Tesla shares to finance the Twitter deal even though the world's richest man had asserted several times that he was done selling Tesla stock.

He sold $6.9 billion worth of Tesla shares in August and had amassed about $20 billion in cash through multiple stake sales from November last year to August.

This would have left him in need to raise an additional $2 billion to $3 billion to finance the Twitter deal, according to a Reuters calculation.

The billionaire last month closed the deal with $13 billion in loans from banks and a $33.5 billion equity commitment, which included his 9.6% Twitter stake worth $4 billion and $7.1 billion from investors including Oracle Corp co-founder Larry Ellison and Saudi Prince Alwaleed bin Talal.

Shares of Tesla were up by 0.7% to $192.64 in premarket trading. The company has lost nearly half its market value ever since Musk bid for Twitter in April.