UPDATE 1-Argentina appeals to US court on pension freeze

(Adds Argentine government appeal)

By Grant McCool

NEW YORK, Nov 20 (Reuters) - Lawyers for the Argentine government and the country's social security administration on Thursday appealed a U.S. judge's orders freezing private pension fund investments in the United States.

District Judge Thomas Griesa of the U.S. Court for the Southern District of New York in Manhattan last Friday extended a freeze he first imposed on Oct. 29 at the request of bondholders to satisfy prior judgment against Argentina on behalf of holders of its defaulted sovereign debt.

The orders were made in a lawsuit by hedge fund Aurelius Capital Partners against the government of Argentina, whose U.S. lawyers filed a notice of appeal with the 2nd U.S. Circuit Court of Appeals.

Separately, the Administracion Nacional de Seguridad Social (ANSES), filed an appeal with the same court to argue that it warrants protection from the freeze under the U.S. Foreign Sovereign Immunities Act.

"We are looking to the court of appeals to review the various restraints on expedition," said New York lawyer Marco Schnabl, who represents ANSES. The agency is not a party to the litigation.

"We were dragged into this when restraints were imposed on us," Schnabl said. "The plaintiffs have argued that this is a permissable thing to do, but we do not believe it is permissable. We hope the court of appeals will referee between these two positions."

Any hearing on the arguments is at the discretion of the appeals court.

On Thursday, Argentine senators were expected to approve a state takeover of $24 billion in private pension fund assets.

The government plan has raised investors' concerns about the country's ability to pay its debts.

The bondholders sued Argentina after refusing to accept huge losses in the country's 2005 debt restructuring, three years after the biggest sovereign debt default in history.

Argentina defaulted in 2002 on some $100 billion in sovereign debt at the height of an economic and political crisis, but about a quarter of its creditors, so-called "holdouts," rejected the deal.

(Reporting by Grant McCool; Editing by Bernard Orr)