By Marianna Parraga and Tom Hals

HOUSTON/WILMINGTON (Reuters) -Venezuela-owned oil refiner Citgo Petroleum has been valued by its parent company at between $32 billion and $40 billion, according to a court official during a hearing in Delaware on Tuesday.

The value of the Houston-based refiner was disclosed during the hearing to update a U.S. judge on talks to enact a court-ordered auction of shares in Citgo's parent to satisfy more than $23 billion in claims against Venezuela and its state oil company PDVSA.

The refiner's value was based on Citgo's earnings of $4 billion before interest, taxes, depreciation and amortization, Ray Schrock, an attorney for a court official, told the court. He said Citgo's parent was seeking an indemnity bond of that value in a related dispute over the parent's share certificate.

Schrock represents a special master appointed by U.S. District Court Judge Leonard Stark in Wilmington, Delaware, to assist with the sale of the shares of Citgo's holding company.

A total of 21 creditors have notified the special master they have claims worth more than $23 billion against Venezuela and PDVSA, Schrock said.

The creditors hope to satisfy those debts by obtaining shares of the company that owns Citgo Petroleum.

Citgo did not immediately reply to a request for comment. Venezuelan President Nicolas Maduro has criticized the auction and said the company "has been kidnapped by the United States."

Citgo is the seventh-largest U.S. oil refiner with plants in Illinois, Louisiana and Texas that can process up to 807,000 barrels per day of crude, and a retail network of more than 4,400 outlets.

The court is expected to approve a sales procedure and schedule, which could see an auction of shares begin as soon as Oct. 23. The process is expected to take at least nine months.

Stark said he will soon decide the estimated dates by which the creditors must complete procedures to obtain writs of attachment to participate in the auction. The special master proposed a date around Jan. 12, the attorney Schrock said, while lawyers representing Venezuela proposed a date of Dec. 22.

(Reporting by Gary McWilliams, Marianna Parraga and Tom HalsEditing by Marguerita Choy and Grant McCool)