Petroleos de Venezuela SA, the state oil company, and Exxon Mobil Corp. (XOM) are negotiating an arbitration settlement of about $6 billion for assets seized by President Hugo Chavez in 2007.

Venezuela will pay any ruling issued by the World Bank’s International Centre for Settlement of Investment Disputes that is in Exxon’s favor, Carlos Escarra, the country’s Prosecutor General, told reporters today in Caracas.

“They started asking for $20 billion,” Escarra said.“Talks dropped to around $12 billion, and now they are around $6 billion. Venezuela has to pay, we are clear on that. The problem now is how much we will pay.”

Chavez, since coming to power in 1999, has nationalized parts of the oil, metals, cement and utilities industries.

In 2007, he forced foreign oil producers into joint ventures as minority partners and is in international arbitration with the Irving, Texas-based Exxon Mobil andConocoPhillips (COP), which rejected revised terms.

Exxon, the world’s largest oil companyy, reduced the amount it is seeking to $7 billion from $12 billion last year.