An investment company controlled by billionaire Patrick Soon-Shiong has taken a roughly 9 percent stake in Jakks Pacific Inc., which recently formed a joint venture with another Soon-Shiong company.

According to a U.S. Securities and Exchange Commission filing late Monday, Soon-Shiong’s California Capital Z LLC, based in Culver City, first acquired a small stake in the Malibu toy company in August, and earlier this month added enough shares to warrant notifying the regulator.

As of Friday, California Capital controlled more than 1.97 million shares, making it Jakks’ third largest shareholder.

Jakks and Soon-Shiong’s West L.A. tech holding company, NantWorks LLC, began discussing a partnership in July. Earlier this month they announced the formation of DreamPlay Toys LLC, which will develop and sell toys and other products using NantWorks’ iDream image recognition technology. DreamPlay plans to start unveiling the products at the Los Angeles Toy Fair next month and the Las Vegas Consumers Electronics Show in January.

Jakks shares earlier closed down 43 cents, or 3 percent, to $13.57 on the Nasdaq.