WASHINGTON, Aug 9 (Reuters) - Tesla Inc (TSLA.O) Chief Executive Officer Elon Musk sold $6.9 billion worth of shares in the electric vehicle maker, tweeting it was important to avoid an emergency sale of Tesla stock amid a legal showdown with Twitter Inc (TWTR.N) over a $44 billion takeover deal.

Musk, the world's richest person, had said in April that there were "no further TSLA sales planned" - after he sold $8.5 billion worth of shares in the company back then.

But legal experts have suggested that if Musk loses his battle against Twitter and is forced to complete the acquisition or pay a stiff penalty, he could conceivably have to sell more Tesla shares.

Musk tore up his April 25 agreement to buy the social media platform and the two sides face a drawn-out legal battle that could still cost Musk billions of dollars. The two sides head to trial on Oct. 17.

In the latest stock sale, Musk sold about 7.92 million shares between Aug.5 and Aug.9, according to multiple filings. He now owns 155.04 million shares in Tesla.

The latest sales bring total stock sales by Musk to about $32 billion in less than one year.