Andris Piebalgs, the EU Energy Commissioner, has expressed concerns that the proposed takeover by Gas Natural of its larger Spanish rival Endesa will be detrimental to the competitive market.

“I view the increasing level of concentration in energy markets with concern,” Piebalgs is quoted in Germany’s Handelsblatt, adding that the Commission would observe market developments very critically.

Piebalgs’ comments also follow German utility E.On’s announced interest in UK generator Scottish Power.