Venezuela's U.S. assets too hard to freeze: Exxon

NEW YORK (Reuters) - ExxonMobil (XOM.N) sought court orders in Europe to freeze $12 billion in Venezuela's overseas energy assets because getting a similar order in the United States before it won its arbitration case against Venezuela's state oil company PDVSA would be too difficult under U.S. law, court papers showed.

"Although PDVSA indirectly owns substantial assets in the U.S. mainly through its U.S. subsidiary, CITGO Petroleum Corporation, I am informed .... that it would be challenging to obtain pre-judgment relief against these assets as a matter of U.S. law," Exxon's UK attorney Thomas Kimpton Sprange wrote in an affidavit in late January before the High Court in Britain.

Exxon filed for arbitration against PDVSA and Venezuela after Caracas nationalized its holdings in the Cerro Negro heavy oil project. Exxon then sought freezing orders in Britain, the Netherlands and the Netherlands Antilles for $12 billion in order to guarantee payment should it win the arbitration.

Similar injunctions in Britain have been used "from time to time," but to win one in the United States is "extremely rare" said Anthony Sabina, professor of law at Tobin Business School at St. John's University in New York.

Citgo, PDVSA's most valuable overseas asset, is the eighth largest oil refiner in the United States, with large plants in Texas, Louisiana and Illinois.

(Additional reporting by Matt Daily; Editing by Marguerita Choy)