Its UK business, which is mainly Scottish Power, is now the biggest contributor to Iberdrola earnings outside Spain.

BBC: Iberdrola profits powered by strong UK performance

Spain's Iberdrola has already scaled back its capital budgets.

FORBES: Magazine Article

Spain -- where Iberdrola is headquartered -- is the eurozone's fourth-largest economy with unemployment at 26.1%, second only to Greece in the single currency bloc, according to Eurostat data.

CNN: Iberdrola CEO: High tax hurting European energy sector

Iberdrola has interests in seven nuclear power plants in Spain, while its subsidiary Scottish Power and SSE, formerly known as Scottish Hydro, are the main customer power supply companies in Scotland.

BBC: Energy giants join up on nuclear

The fight between Repsol YPF , a Spanish energy concern, and Endesa , Spain's leading electricity provider, for the second-biggest generator, Iberdrola, has ended in a government-sanctioned settlement.

ECONOMIST: Sweet deals

It is Gas Natural's third attempt to hook up with a big partner in Spain's rapidly consolidating power industry, having been rebuffed by Endesa in 2005 and Iberdrola in 2003.

ECONOMIST: Business this week | The