Two Argentine subsidiaries of the oil company Chevron have appealed against a court order freezing up to $19bn of their assets, according to BBC News.
A judge issued the order as part of an environmental damages claim in Ecuador.
Chevron has been ordered to pay $19bn for polluting land in the Amazon region but because it has few assets in Ecuador the plaintiffs are trying to get the ruling enforced abroad.
Chevron said the subsidiaries had nothing to do with the judgment.
"Chevron Corp, the sole judgment debtor, has no assets in Argentina," Chevron spokesman Kent Robertson said. "All operations in Argentina are conducted by subsidiaries that have nothing to do with the fraudulent judgment in Ecuador," according to him.
Wednesday's court order freezing Chevron's assets in Argentina is the latest move in a decades-long legal wrangle between Chevron and the people of the Lago Agrio region of Ecuador.
The Ecuadorean court judgment originally ordered Chevron to pay $8.6bn in environmental damages, but that was more than doubled because the oil company did not apologize publicly.
The Ecuadorean plaintiffs say that Texaco, which merged with Chevron in 2001, dumped toxic materials in the Ecuadorean Amazon between 1964 and 1992.
Chevron says Texaco spent $40m cleaning up the area during the 1990s, and signed an agreement with Ecuador in 1998 absolving it of any further responsibility.
Chevron has in the past said the original ruling against the company was a product of "bribery and fraud".
The company has also dismissed the plaintiffs' moves to get the ruling enforced abroad, saying that "if the plaintiffs' lawyers believed they had a legitimate judgment, they would seek to enforce it in the United States".
