Spain's Telefonica has filed a 500 million euro ($623 million) international arbitration claim against Mexico, saying the lower fees rivals are allowed to pay to connect to its local unit's network have hurt its ability to invest.

The World Bank's International Center for the Settlement of Investment Disputes, meanwhile, announced on its Web site that it has agreed to hear the telecom firm's complaint.

Telefonica says Mexico's current interconnection fee regulations violate an investment treaty that country signed with Spain in 2008.

Spokespersons for the Spanish company told Efe the operator notified the Mexican government in September 2011 of its plans to seek international arbitration.

In keeping with the terms of the bilateral treaty, Telefonica waited six months before lodging its complaint on March 9 with the World Bank tribunal, which agreed to hear the case last week.

The operator said it is confident the ICSID will resolve the matter in its favor and noted that it has already received beneficial rulings in Mexico on issues such as the "double window" (the overlapping of regulatory decisions by two separate bodies) and the securing of a declaration stating that America Movil unit Telcel is the country's only dominant wireless operator.

Carlos Slim-controlled Telcel has roughly a 70 percent market share, while Telefonica's Mexico unit is a distant second with about 20 percent of cellular subscribers. EFE