As crisis-plagued Venezuela struggles to pay its bills at home and abroad, foreign creditors are circling one of the country's most valuable assets: Citgo, the Houston-based oil company that it has owned since 1990.

If Citgo is seized and sold to pay Venezuela's debts, it could disrupt one of the most reliable sources of cash for a country already reeling from hyperinflation, food and medicine shortages, and a population exodus. U.S. sanctions aimed at pressuring President Nicolás Maduro, who has overseen the worst of the country's implosion, have exacerbated the government's pain, largely blocking it from the U.S. financial system.

The fight over Citgo is unfolding in courtrooms and boardrooms across North America and Europe - with a key decision expected by the end of the year.

Two Canadian mining firms are trying to acquire parts of Citgo as compensation for Venezuela's expropriation of their assets more than a decade ago. A Russian oil company and holders of bonds issued by Venezuela's state oil producer have staked a claim to Citgo shares. ConocoPhillips suggested it may also pursue the company.

In August, a federal judge in Delaware gave a bankrupt Canadian gold-mining company, Crystallex International, permission to seize shares of Citgo's holding company, a decision that Venezuela's lawyers lamented would "trigger a cascade of adverse events."

Now the other creditors are waiting to see whether the judge allows Crystallex to begin selling those shares - which could trigger even more claims on Citgo.

Venezuela faces more than $10 billion in immediate claims from foreign entities. "The pool of creditors is much larger than the pool of available ways to get paid," said Russ Dallen, a Florida-based managing partner at the brokerage Caracas Capital Markets. "Citgo is the most valuable asset out there."

Citgo's Gulf Coast refineries are big buyers of Venezuela's crude oil. The Houston company is one of the few customers from which Venezuela can expect same-day payments, Dallen said. It is possible that a new Citgo owner would carry on buying from Venezuela with little interruption, but it's also possible that new ownership would destabilize those purchases, he said.

Oil exports account for more than 90 percent of Venezuela's hard-currency earnings. That money is "absolutely necessary for keeping the regime afloat," said Monica de Bolle, director of the Latin American studies program at the Johns Hopkins School of Advanced International Studies. Disrupting it "would tighten the noose around the Maduro regime."

Petróleos de Venezuela (PDVSA), the state oil company that owns Citgo, appealed the Delaware court ruling, saying it could "jeopardize the financial well-being" of PDVSA and Citgo. PDVSA and the Venezuelan Communication Ministry did not respond to requests for comment.

Citgo was founded in 1910 by American businessman Henry Doherty and traded hands a few times before PDVSA bought full control. Citgo owns refineries in Texas, Louisiana and Illinois and pipelines and petroleum distribution terminals across the United States. The company sells fuel to Citgo-branded gasoline stations that are owned by local entrepreneurs.

U.S. sanctions have reduced Venezuela's ability to benefit from Citgo, barring the firm from sending dividends to Caracas. The United States did not issue sanctions preventing Venezuela from selling oil to Citgo because the U.S. market depends on those imports.

Creditors' tug of war over Citgo is unfolding as Venezuela's economic crisis deepens. Malnutrition and poverty are soaring, power and water infrastructure is failing, and inflation is rocketing toward 1 million percent. Venezuelans are fleeing their broken nation by the hundreds of thousands in the region's largest migrant crisis in decades.

The country's oil industry, meanwhile, is crumbling. Drill sites and pipelines are being raided by bandits and failing because of mismanagement and a lack of spare parts. Oil output has slumped to levels not seen since at least the 1950s.

Amid the breakdown, Venezuela and PDVSA last year stopped making payments on some of their foreign debt, which probably exceeds $150 billion, according to Siobhan Morden, head of Latin America fixed-income strategy at Nomura Securities. Firm figures on the country's debt are unavailable because Caracas has stopped reporting that data, she said.

The country is also facing large claims from foreign companies whose mining and oil assets were nationalized under the previous government of Hugo Chávez, the leftist firebrand who died in 2013.

In 2016, an international arbitration panel ruled that Venezuela owed Crystallex $1.2 billion plus interest as compensation for nationalizing the Las Cristinas gold mines, a seizure that pushed Crystallex into bankruptcy.

With the Delaware court ruling, PDVSA was found liable for Venezuela's debts, and Crystallex was granted permission to take over the state oil company's shares in a subsidiary that owns Citgo Holding. The court told Crystallex to hold off selling the shares until it fielded objections from other parties.

Banks and pension funds that hold $1.5 billion of PDVSA bonds secured by a majority stake in Citgo Holding have requested a delay in the share sale until the appeal is decided.

The Russian state-controlled oil company, Rosneft, which holds 49.9 percent of Citgo Holding as collateral against loans it provided to PDVSA, also stepped forward, saying a change in Citgo ownership could give it the right to sell that collateral.

And ConocoPhillips, which is trying to recover $2 billion from PDVSA in connection with Venezuela's oil industry nationalization, asked the court to delay the share sale, saying the appeal ruling could make Citgo available to PDVSA creditors like itself.

Citgo isn't the only Venezuelan asset creditors have pursued. This spring, after winning a $2 billion arbitration award against PDVSA, ConocoPhillips tried to seize Venezuelan crude oil in storage facilities across several Caribbean islands. The move disrupted Venezuela's crude exports and left the country scrambling to bring its tankers back into national waters to protect them from seizure.

Andre Agapov, chief executive of Vancouver-based Rusoro Mining, said he traveled to Caracas this summer to speak with Attorney General Reinaldo Muñoz about recovering a $1.4 billion debt related to Venezuela's nationalization of gold-mining assets.

This month, Rusoro said it had reached a settlement with Venezuela for $1.28 billion.

Until Venezuela begins paying the mining company, though, Rusoro is continuing to pursue a court case in Texas to lay claim to Citgo assets, according to Jay Kaplowitz, a lawyer for the company. That case won't be withdrawn "until after the first payment is made," he said.