Iberdrola’s sales gained four percent over the year to 31.6 billion euros however, and core operating profit was 1.6 percent higher at 7.65 billion euros, a statement said.

Spain, which has the eurozone’s fourth biggest economy, is grappling with heavy debt and deficits and the latest data shows that national output shrank by 0.3 percent in the fourth quarter of 2011.

The country is expected to struggle through a recession this year before recovering in 2013.

On Saturday, Industry Minister Jose Manuel Soria said Spain would extend operations at its oldest nuclear power plant, owned equally by Iberdrola and Spanish rival Endesa, by five years.