Venezuela's state-run oil company will terminate all ventures with Exxon Mobil (NYSE: XOM), the biggest U.S. oil company, when arbitration proceedings conclude, Oil Minister Rafael Ramirez said.

The dispute between Petroleos de Venezuela SA and Exxon Mobil stems from the 2007 nationalization of foreign oil assets by President Hugo Chavez.

ConocoPhillips (NYSE: COP) also had assets confiscated. 

Exxon Mobil spokesman Patrick McGinn said the only joint venture the company has with PDVSA is a shared stake in the Chalmette Refinery in Louisiana. Exxon Mobil had no other comment.

PDVSA wants to upgrade one of its facilities into a full refinery so that Venezuelan crude oil doesn't have to leave for the U.S. for refining, Bloomberg reported.

The Chalmette facility can refine as much as 192,000 barrels of oil a day.

Exxon Mobil has been wrangling in arbitration court in Washington, D.C. for the fair market price of its seized holdings in Venezuela.

A final determination could come as soon as year-end or 2013, Ramirez told the daily El Mundo, Bloomberg reported.

Chavez offered to reimburse Exxon Mobil what would have been the book value of the company's holdings. ExxonMobil demanded more. That led to the current arbitration.

In January, the International Chamber of Commerce ruled in favor of Chavez, ordering his government to pay $907 million from PDVSA to Exxon Mobil in fair compensation, roughly the book value of the company's holdings. Meanwhile, analysts estimated the market value could likely be calculated in the billions of dollars.

The International Centre for Settlement of Investment Disputes in Washington, D.C. hasn't made a final ruling on the matter.

Shares of ExxonMobil rose 70 cents to $86.78 in Friday afternoon trading.