It's not uncommon to see the state-run oil company PEMEX at the center of controversies regarding the designation of energy resources as the national patrimony of the nation's citizens. This debate has often been in connection with Mexico's crude oil, natural gas, and PEMEX itself. In late August, PEMEX found itself on the other side of the conflict when it teamed up with Spainbased construction and real estate company Sacyr Vallehermoso to boost their share of Spanish giant Repsol YPF SA. The two companies acknowledged that their intention was to restructure Repsol's management. Even though Spain's Constitution does not have a provision reserving energy resources as national patrimony, questions arose on whether Repsol, a symbol of Spain around the globe, would remain sufficiently "Spanish."
Navarro, Carlos. "PEMEX Boosts Participation in Spain's Repsol, Prompting Some Nationalist Concerns in Spain." (2011). http://digitalrepository.unm.edu/la_energy_notien/79