A law firm that previously represented a small investment company is not barred from representing one of the two equal shareholders in litigation adverse to the estate of the other, a state judge has ruled.

The estate of investment manager John F. Beiter, who died suddenly last August, had sought to disqualify Willkie Farr & Gallagher from representing Beiter’s former partner, Niklas Lamotte, in a dispute over the disposition of Beiter’s interest in Resolution Partners, the investment company they co-founded.