A World Bank arbitration panel Thursday ruled that the Venezuelan government must pay ExxonMobil $1.6 billion to compensate for taking control of the US firm’s heavy-oil project in the country.

A three-member arbitration panel for the Washington-based International Centre For Settlement of Investment Disputes (ICSID) unanimously granted the award to the biggest US oil company following the June 2007 expropriation of the Cerro Negro project in Venezuela, a heavy-oil region known as the Orinoco Belt.

The panel rejected arguments offered by ExxonMobil that Venezuela’s taking of the Orinoco property represented an illegal expropriation.

However, the panel said the award was warranted as “just compensation” under an international investment treaty signed by Venezuela.

The panel set the $1.6 billion figure based on an analysis of future revenues and expenses of the Cerro Negro project that looked at expected oil prices, among other factors.

The ICSID decision against Venezuela follows a January 2012 judgement against state-owned oil firm Petroleos de Venezuela of $750 million by the Paris-based International Chamber of Commerce over the Cerro Negro expropriation.

ExxonMobil had sought some $12 billion following the 2007 seizure. The 2007 seizure followed a number of toughened commercial terms imposed on foreign oil companies by Venezuela over the multibillion-dollar oil project begun in the 1990s.