HOUSTON, Jan 8 (Reuters) - A U.S. judge on Monday granted a large group of Venezuela-linked creditors rights to participate in a January auction of shares in the parent of Houston-based refiner Citgo Petroleum.

A precedent-setting lawsuit by Canadian miner Crystallex Corp formally tied Venezuela-owned Citgo to the South American country's debts and opened the door to some $24 billion in claims being applied to the refining firm through an auction of shares in a Citgo parent whose only asset is the oil refiner.

The decision still requires the group, formed by 10 companies, to comply with a Jan 12 dateline to have writs of attachments issued against shares in Citgo's parent, PDV Holding. No extra time was granted, and a new auction schedule issued on Monday is not planned to be modified, the court in Delaware said. The U.S. Treasury also has reserved the right to rule on any winning bid.

O-I Glass, Huntington Ingalls, ACL1 Investments, Rusoro Mining, Koch Industries and Gold Reserve can have claims considered as additional judgments. Another group of four creditors including Siemens Energy that had filed a similar motion to be designated additional creditors were also green-lit, U.S. Judge Leonard Stark ruled.

The companies had sought to participate "with full force and effect" in the event two of the largest creditors in the long-running case - miner Crystallex and oil firm ConocoPhillips - reach settlements with Venezuela that could end the lawsuit.

Talks have been on and off for months with holders of billions of dollars due for asset expropriations and defaulted Venezuelan bonds seeking to settle their claims.

The additional creditors had argued they needed to have equal status to protect their interests in event of a deal and to organize their own credit bids, using their claims against the purchase price in any sale.

(Reporting by Marianna Parraga and Gary McWilliams)