An attempt by Chevron Corp to unfreeze its assets was dismissed by an appeals court in Argentina, where the winners of a US$19 billion environmental judgment in Ecuador are suing to force the oil company to pay.

Plaintiffs' attorney Pablo Fajardo told The Associated Press that the court refused to lift an embargo that a lower-court judge imposed in November in the case, which involves oil contamination left after Texaco Corp pulled out of the Amazon decades ago. Chevron later bought Texaco and inherited the problem.

"Chevron respectfully disagrees with the court's decision" and will pursue all available legal remedies to reverse the interim measure, spokesman Kurt Glaubitz said.

Chevron has no assets in Ecuador, so the plaintiffs have filed suits in Canada, Brazil and Argentina.

Chevron has refused to pay, saying that if the accusations had been legitimate, the plaintiffs would be seeking relief in the United States, where the company is headquartered.

Each side has accused the other of committing fraud during the long judicial process, which began in the United States but moved to Ecuador with Chevron's consent at a time when the country was led by interests more sympathetic to foreign oil companies than its current president, leftist Rafael Correa.

- AP