In a lawsuit launched by former shareholders of energy company YPF, who were backed by Burford Capital, against the government of Argentina, a US Federal judge entered a $16 billion judgment against the Argentinian government and in favor of the investors.

The lawsuit arose from Argentina’s seizure of a majority stake in the oil and gas company in 2012. The case was seen as a defeat for the government of Argentina, which was ordered to pay $8.4 billion in damages and $7.6 billion in interest to two former investors in YPF, Petersen and Eton Park.

Shortly after the decision was published on Friday, shares of Buford Capital, a litigation finance giant which was largely responsible for funding the plaintiff’s lawsuit, jumped by 28% in US trading.

In a statement, the government of Argentina said the ruling was “unprecedented and erroneous,” and said it would appeal the ruling.

The statement said, “This case over the rights of former shareholders of an Argentine company under the Argentine company’s bylaws does not belong in a US court.”

The Argentinian government took control of 51% of YPF in 2012 after its majority shareholder, the Spanish company Repsol SA, was accused of failing to invest enough resources in oil production. The parties reached an agreement in 2014 under which the Spanish firm was given $5 billion in compensation.

Buford Capital then went on to purchase the companies which had owned 25% of the shares of YPF prior to the nationalization.

Argentine government spokeswoman Gabriela Cerruti posted on Twitter.com, “We will continue to defend energy sovereignty and our state company YPF against vulture funds.”