MADRID/DUBAI - Abu Dhabi's TAQA is in talks with Spanish holding vehicle Criteria over a potential takeover of Spanish energy company Naturgy, newspaper Cinco Dias reported on Tuesday citing unidentified market sources.

ADPower, a unit of Abu Dhabi sovereign wealth fund ADQ, owns just over 90% of TAQA.

TAQA would have to launch a full takeover bid for the whole company, as Spanish legislation requires a mandatory tender offer when a buyer wants to acquire more than 30% of any publicly traded company.

The negotiation started over a month ago with the knowledge of the Spanish government, Cinco Dias added in its report.

Criteria, which is the main shareholder in lender Caixabank , owns a 26.7% stake in Naturgy. Private equity investment funds GIP and CVC each own around a 20% stake.

Naturgy and Criteria declined to comment. TAQA did not immediately respond to an emailed request for comment.

(Reporting by Jesús Aguado, Pietro Lombardi and David Latona in Madrid, and Yousef Saba in Dubai; Editing by Inti Landauro and Louise Heavens)