By Tracy Rucinski

CHICAGO (Reuters) - A U.S. bankruptcy judge said on Wednesday he must look deeper into whether he has the authority to halt bondholder lawsuits against Caesars Entertainment Corp <CZR.O> in New York and Delaware given that proceedings have already begun.

Several hedge funds are suing the casino company for a total of $11.4 billion, saying it reneged on guarantees on bonds issued by its unit, which filed for bankruptcy in January 2015. Caesars plans to pump about $4 billion to help restructure the unit, called Caesars Entertainment Operating Co.

Legal action against the parent could jeopardize the funding and force it into bankruptcy as well, the unit argued in seeking an injunction to stop the lawsuits.

U.S. Judge Benjamin Goldgar said in bankruptcy court in Chicago that he may not have the power to stop the courts or parties involved from proceeding with the cases because they are already in motion.

"I'll take a look (at prior case law) when there's more time," Goldgar said.

Caesars has the right to terminate its funding agreement by June 22 if the judge does not halt the lawsuits by June 15, the unit's lawyers said at the hearing.

Shares of Caesars fell 5.6 percent to $8.19 on Wednesday.

Jim Millstein, a financial adviser to the bankrupt operating unit, testified that the parent company might have to file for bankruptcy protection if it was hit with billions of dollars in damages from the bondholder cases.

Millstein estimated that since the unit filed for bankruptcy, it has spent $900 million a year on interest payments on first-lien bank and bond debt and $200 million a year on administrative expenses.

A bankruptcy filing by the parent would cost another $200 million a year in expenses that would have priority over creditors' claims, he added.

"Time is not our friend," he said.

The Caesars unit has yet to secure support from first-lien banks or its junior creditors for its reorganization plan.

An independent examiner concluded in March that Caesars and its private equity sponsors, Apollo Global Management LLC <APO.N> and TPG Capital [TPG.UL], could face $5 billion in potential damages from the unit's bankruptcy. Junior creditors say they have claims worth as much as $12.6 billion.

(Reporting by Tracy Rucinski; Editing by Richard Chang)