The World Bank\'s arbitration unit has agreed to hear a complaint by Spanish oil firm Repsol over Argentina\'s expropriation of the company\'s former energy affiliate YPF. On its website, the International Center for Settlement of Investment Disputes simply indicated that it had begun the arbitration process on Tuesday and the tribunal was \"not yet constituted.\" Repsol filed its complaint two weeks ago. The two parties now must agree on the members of a three-person tribunal which will review the case. In May, the Argentine government seized YPF from Repsol, accusing the Spanish oil giant of allowing oil and gas production to lapse and forcing Argentina\'s oil import bill to rise amid growing demand. Repsol is fighting for financial compensation over the expropriation. It has filed suit against Argentina in a New York court, saying the government violated YPF bylaws with the takeover. The Spanish firm says its 51 percent stake in YPF is worth $10 billion. It has also threatened to take to court any party investing in YPF interests, which it says were expropriated illegally. Earlier this month, US oil giant Chevron announced a deal to tap shale oil resources in western Argentina with YPF. Repsol has filed lawsuits in Spain and the United States to block the plan.