Venture Firm Seeks Bankruptcy in Fight With Russian Billionaire

A US venture firm is seeking bankruptcy protection for some of its affiliates, marking the latest fallout from a dispute with Russian billionaire Dmitry Rybolovlev’s family trust over investments in companies that develop life-science products.

Apple Tree Partners filed in Delaware for Chapter 11 restructuring of entities owned by Rybolovlev’s family trust — called Rigmora — and the venture firm’s founder Seth Harrison. Rigmora is the lone outside funder for Apple Tree under a years-long partnership, but their relationship fell apart earlier this year.

“We undertake this restructuring to serve the best interests of our limited partners, our ...