HOUSTON, Jan 24 (Reuters) - A federal judge in Delaware on Wednesday allowed an additional creditor to seek proceeds from an auction of shares in a parent of Citgo Petroleum, which could lead to an ownership change of the seventh U.S. largest oil refiner to pay for Venezuela's pending debts.

Judge Leonard Stark's decision clearing Altana Credit Opportunities Fund's $530 million claim increases the total of claims allowed by the court to some $21.3 billion from a cut of $20.8 billion announced earlier this month.

Another creditor presenting a nearly $17 million claim, Ricardo Devengoechea, will be given extra time to comply with court requirements to attach his claim, Stark said.

Citgo, ultimately owned by Caracas-headquartered state firm Petroleos de Venezuela, has been valued in between $11 billion and $13 billion. The auction is not expected to satisfy all claims allowed.

The court years ago found Citgo parent, PDV Holding, liable for Venezuela's expropriations and debt defaults, bringing dozens of other creditors to press their claims.

The judge has said the whole sale process might be completed in a year from its launch last October.

PRIORITY CLAIMS

Stark last year gave priority to miner Crystallex to cash some $990 million in proceeds from the auction, while granting oil producer ConocoPhillips a position near the front of the line to cash a $1.33-billion claim, one of the three awards the company has registered with the court.

Both companies remained among the top three creditors in a list updated by the court last week. A $72 million claim by offshore service provider Tidewater has been moved to second place.

Near the top of the list to collect proceeds are glass maker O-I Glass, Huntington Ingalls Industries, ACL Investments, Red Tree Investments, Rusoro Mining, a second, $48.1 million claim by Conoco, and units of Koch Industries.

Stark has kept most of the bidding rounds' details confidential, including bidder names. The court last year hired investment banker Evercore Group to market Citgo's assets, which include three refineries, terminals and pipelines; and so far has established a first-come-first-served priority order.

Here is the court's participation criteria:

CRYSTALLEX IS FIRST

Miner Crystallex introduced its claim in Delaware in 2017, becoming the first creditor with a confirmed arbitration award against Venezuela and earning top priority.

The miner is the only company that has completed all conditions set by the court to seize foreign property owned by PDVSA. PDV Holding is a PDVSA subsidiary whose only asset is Houston-based Citgo Petroleum.

Other Venezuela creditors tried to follow the same path, but had been prevented by U.S. sanctions on Venezuela. Stark has awarded them conditional writs of attachment.

BIDDING AND PAYMENT

Potential investors and energy companies this month submitted bids for shares in PDV Holding in a first bidding round. There could be a second round in the second quarter. All proceeds will be used to pay creditors.

Delaware law concerning the enforcement of money judgments generally requires that sale proceeds be distributed according to a "first in time, first in line" rule.

But in this case, the court also is taking into account the unique factors of the Venezuela case, so that rule might not be absolute, lawyers close to the sale process said.

The court might decide to bifurcate the sale process to avoid delays, allowing bidding for the shares to be separate from any decision on ranking creditors who could participate in the auction, one of the lawyers said.

(Reporting by Marianna Parraga; Editing by Daniel Wallis, Leslie Adler, Alexandra Hudson)