Spain will ask the European Union to file a complaint with the World Trade Organization against Argentina for seizing control of energy company YPF, which is majority owned by Repsol, a high-ranking government source said on Wednesday.
The source did not wish to be named and gave no further details.
Madrid has threatened economic and diplomatic consequences for Argentine President Cristina Fernandez's decision to nationalise 51 percent of YPF owned by Spanish oil major Repsol.
EU foreign ministers will debate how to deal with the Spanish-Argentine row at a meeting on Monday.
Spain will also decide its own measures against Argentina at a cabinet meeting on Friday, the source said, while the European Parliament will discuss the dispute between Spain and Argentina on Wednesday.
However, Madrid may find it hard to put pressure on a nation that has been shut out of world debt markets and has ignored international fines in previous disputes.
(Reporting By Andres Gonzalez; Additional reporting by Eric Holmberg in Brussels; Writing by Tracy Rucinski. Editing by Jeremy Gaunt.)