soon revealed that the German energy group E.ON, which also owns Powergen, was interested in a takeover. On 22 November 2005, the board rejected an offer from E.ON of 570 pence per share, which would have valued the group at £10.7 billion.

On 28 November 2006, the board of directors of ScottishPower agreed to an £11.6 billion takeover bid by the Spanish energy firm Iberdrola. The offer was formally approved by shareholders at an EGM