Ecuadorean plaintiffs have appealed a U.S. judge's decision to allow Chevron Corp to seek arbitration of a case of alleged pollution in the Amazon rainforest with a potential $27 billion liability. The plaintiffs, indigeneous Ecuadoreans, filed the notice of appeal…a week after a judge ruled in favor of [Chevron] in its efforts to seek international arbitration. Chevron cites violations under the U.S.-Ecuador Bilateral Investment Treaty in the case…The company says Ecuador breached the treaty by not forcing that [Ecuadorean] court to dismiss the lawsuit…Chevron says Ecuador and…Petroecuador, Texaco's partner there, released Texaco from further liability…after [its] share of remediation work was complete. The validity of that release, however, is disputed by the plaintiffs.