European Union antitrust regulators approved the takeover of Spain's largest utility Endesa by Acciona and Italian utility Enel on Thursday.
The European Commission said that its investigation found that the proposed deal "would not significantly impede" competition in the EU energy market.
The EU's greenlight to the 43.7 billion euros ($59.51 billion) deal brings to an end the bidding war for Endesa which raised EU concerns over apparent Spanish efforts to keep Endesa out of foreign hands.