A Madrid court has halted the hostile cash and stock bid of about €22 billion for Endesa from Spain's biggest gas distributor Gas Natural until it rules on whether the proposed transaction violates European Union competition regulations.

Endesa, Spain’s biggest electricity utility, claimed in October that Gas Natural acted in collusion with Iberdrola SA, the country’s second largest power company, when the latter signed an exclusive agreement to buy some Endesa assets

if the planned takeover went through. Gas Natural and Iberdrola claim that Endesa is merely trying to block the bid by whatever means it can, and is hurting shareholders in the process.

In reality, Gas Natural’s bid hinges on whether competition authorities approve a €29.1 billion all-cash counterbid from German utility E.On. But according to Endesa even this higher offer does not adequately reflect Endesa’s real value.

The deal, if successful, would create one of the world’s leading power and gas companies serving more than 50 million customers in more than 30 countries.