HOUSTON, June 4 (Reuters) - Members of Venezuela's political opposition and the boards that supervise state-owned refiner Citgo Petroleum have met U.S. officials and lawmakers in recent days in a new effort to pause a court-ordered auction of shares to pay creditors, people close to the talks said.

A second bidding round for shares in Citgo's parent company PDV Holding is expected to close on Tuesday, the final step in a years-long process expected to result in a change of ownership of the seventh-largest U.S. refiner.

WHY IT'S IMPORTANT

A total of 18 creditors including ConocoPhillips, Koch Industries and miners Crystallex, Rusoro and Gold Reserve, aim to cash up to $21.3 billion in claims.

But the highest offer in the first bidding round did not reach $8 billion, prompting Citgo's supervisory boards to protest and present an alternative payment option.

If successful, the talks could result in a change of U.S. policy guidance issued by the Biden administration, which last year gave a green light to the U.S. District Court in Delaware to move forward with the auction.

Citgo and its supervisory boards did not immediately respond to requests for comment.

WHAT'S NEXT

The Venezuela representatives want a pause in the court process at least until results are known from the Venezuelan presidential election in July.

BY THE NUMBERS

Citgo has plants in Louisiana, Illinois and Texas that can jointly process 807,000 barrels per day of oil. In the last two years, the company has generated $4.8 billion in combined net earnings. (Reporting by Marianna Parraga; Editing by Jamie Freed)