(Adds details of the case)
MEXICO CITY, Nov 24 (Reuters) - Mexican billionaire Carlos Slim's infrastructure firm Ideal on Monday said a seizure order by a Panamanian court targeting some of its assets was unlawful.
The order stemmed from a legal battle over the ownership of a concession to operate the Bajo de Mina hydroelectric plant in the Central American country.
The plant concession was first granted to Panamanian businessman Julio Cesar Lisac in 2006, but authorities revoked it and awarded it to Slim, newspaper La Estrella de Panama reported.
A 2010 Supreme Court ruling in favor of Lisac was never executed, the paper added.
Ideal said on Monday the seizure order failed to comply with the law and did not specify the assets to be seized.
It added that Panama's government had taken the concession from Lisac in 2012 and said it was still awaiting the decision of an appeal process started by the company and the country's public services authority ASEP.
La Estrella de Panama said the seizure order involved about 10 properties owned by Ideal.
A spokeswoman for the Supreme Court of Justice confirmed that the Fifth Civil Circuit Court had issued a resolution in the concession case but added that details would not be made public until it had been executed.
Reporting by Christine Murray and Alexandra Alper; Additional reporting by Eli Moreno in Panama City; Editing by Tom Brown