The European Union has urged Argentina today to respect the rights of foreign investments as it voiced concern over reported plans to nationalise a unit of Spanish oil firm Repsol.

The European Commission, the EU's executive arm, said its delegation in Buenos Aires had expressed its concerns directly to the Argentine government.

"We underlined the need for all parties to find solutions together and not harm the working environment and economic relations between the European Union and Argentina," commission spokesman Olivier Bailly told a news briefing.

"We hope that Argentina respects its international commitments on the protection of foreign investments on its soil and we are on Spain's side in this situation," he said.

Spain summoned Argentina's ambassador today to raise concerns over the fate of Repsol's subsidiary YPF.

Argentina accuses the company of failing to meet commitments linked to oil-drilling in the country.

Governors in 16 provinces of Argentina have revoked petroleum concessions held by Repsol-YPF in recent weeks.

Argentine authorities accuse it and other major firms of inadequate production and of not investing enough in Argentina.

President Cristina Kirchner met with provincial governors on Thursday. The governor of the oil-producing province Neuquen, Jorge Sapag, said the meeting was to discuss transforming Repsol-YPF into a joint state and private venture.