Argentine state explorer YPF has been fined around $500 million by an international arbitration court over contract cancellations relating to natural gas exports to Brazil in the last decade, the company said on April 27.

"YPF will use all its legal resources to defend its interests and those of its shareholders, and considers the arbitration ruling void," it said.

Plaintiffs were seeking compensation for rescission of contracts with Transportadora de Gas del Mercosur (TGM) and AES Uruguaiana (AESU) in 2009.

The International Chamber of Commerce (ICC) has ruled that YPF should pay TGM $319 million and AESU $185 million, YPF said in a statement to the stock exchange.

The Paris-based ICC's court of arbitration's rulings are binding, final and susceptible of enforcement anywhere in the world, according to its website.

At the time of the disputed contracts, YPF was controlled by Spain's Repsol. Argentina suspended sales of natural gas to neighboring Brazil and Chile in 2004, when its production began to fall.

Transportadora de Gas del Mercosur operates an Argentine pipeline that runs up to the border with Brazil. Its shareholders include Argentina's Techint, France's Total , Malaysia's Petronas and U.S.-based CMS Energy.

AESU belongs to power utility AES Brasil, the Brazilian unit of U.S. energy giant AES Corp.

The ruling comes the same week as YPF has returned to exporting crude oil for the first time in years.