“We are quite taken aback by this,” Tim Osborne, a British tax lawyer and the director of GML, a company that controlled a majority of Yukos shares, said in an interview. Mr. Osborne said that GML would appeal the case in The Hague.

Paying out $50 billion would be a strain for Russia, which has fallen into recession because of low oil prices and Western sanctions. Russia had revenue of $130 billion from oil exports last year, but the plunge in prices since mid-2014 means the country might make even less from petroleum this year.

The Russian government voiced pleasure over the ruling on Wednesday.

“If these men continue to try to exploit the international courts to take money from the Russian people, we will show Yukos engaged in massive tax fraud throughout its existence, and fight them in every court and every jurisdiction,” said Andrey Kondakov, director general of the International Center for Legal Protection, which the Russian government set up to fight the case.

The arbitration panel that ruled against Russia in 2014 had met in The Hague and had been chosen jointly by Yukos and the Russian Federation. That is why the appeal was heard by the Dutch district court that ruled on Wednesday. Its decision, in turn, could be appealed to higher Dutch courts.

GML is pursuing legal efforts to collect the Russian money in a half-dozen other countries: Belgium, Britain, France, Germany, India and the United States. There have not yet been rulings in those cases, and it was not immediately clear on Wednesday how the decision in The Hague might affect them.