(Reuters) - Bidders in a U.S. court auction of shares that will decide the ownership of oil refiner Citgo Petroleum can be required to say if their binding offers cover claims by Venezuela bondholders in a separate court action, a U.S. District Court judge ruled on Friday.

The decision lets bidders seeking to place multi-billion dollar offers for a Citgo parent's shares to be asked if they plan to set aside cash or if their bids will accommodate Venezuela 2020 note holders seeking payment of $3 billion in principal debt.

The ruling by US Judge Leonard Stark came after Venezuela objected to a court officer's revised bidding instructions that Venezuela and some creditors called unclear. Stark rejected the motion to delay the auction, saying the court officer could make changes to maximize the value of bids received.

(Reporting by Gary McWilliams)