Spain's Criteria group will seek a new partner for a possible takeover bid for Spanish gas company Naturgy as soon as possible after it recently failed to reach an agreement with Abu Dhabi's TAQA, a person familiar with the plans said Monday.

Asked whether it has to be an industrial partner from the energy sector, the source said Criteria -- which owns a 26.7% stake in Naturgy -- is open to any type of shareholder that brings growth to the company.

The source added that Criteria does not like to act alone when it comes to companies it considers strategic.

(Reporting by Joan Faus; editing by Aislinn Laing and David Latona; Spanish edition by Benjamín Mejías Valencia)