The three-month extension provides time for a board supervising Citgo to negotiate settlements with creditors, but would not stop the auction in a U.S. District Court in Delaware.

Half of the refiner's shares are collateral for 2020 bonds issued by Citgo's ultimate parent, Venezuela's state oil company PDVSA. The holders of those bonds and Venezuela are fighting in a New York court.

Creditors aiming to cash about $24 billion from expropriations and debt defaults have flocked to Delaware to have their court rulings and arbitration awards accepted. The auction could lead to change of ownership in the seventh-largest U.S. largest oil refiner.

The first bidding round as part of the sale process has been set by U.S. Judge Leonard Stark for next Monday, Jan. 22. A final list of the creditors cleared to participate is expected to be published by the court ahead of the auction.

The U.S general license was posted in a notice at the Treasury Department's website.

(Reporting by Daphne Psaledakis and Marianna Parraga; writing by Paul Grant; Editing by Ismail Shakil)