The court rejected arguments by the Prussian Cultural Heritage Foundation (SPK) that the $250m claim should be dismissed – although it has removed Germany as a defendant in the case.
The long-running case, which moved to the US in 2014 after a committee in Germany concluded that restitution was not appropriate, centres on the Guelph Treasure in Berlin’s Kunstgewerbemuseum.
The heirs of three Frankfurt art dealers claim that in 1935 the Nazis forced their families to sell the 44 pieces at 35% of the market price.
The heirs are demanding the return of the objects or $250m.
The lawsuit is among the first heard under the Holocaust Expropriated Art Recovery Act, signed into US law in December 2016.
The act has eliminated statute-of-limitations hurdles, making it easier for Nazi-related restitution claims to be filed in the US.