A Twitter shareholder is suing Elon Musk, claiming he and others suffered financial losses because of the billionaire's delay in disclosing his stake in the social-media company.

In a lawsuit filed 12 April in the Southern District of New York, Marc Bain Rasella claims Musk made "materially false and misleading statements and omissions by failing to disclose to investors" his 9.2% ownership stake in a timely manner, in violation of Securities and Exchange Commission regulations.