Iberdrola's U.S. unit Avangrid Inc , has terminated its $8.3 billion deal, including debt, for competitor PNM Resources as it was unable to obtain all regulatory approvals needed to close by Dec. 31, the U.S. utility said in a statement on Tuesday.

The two utilities had obtained all necessary approvals except from the New Mexico Public Regulation Commission, the statement said.

The regulator had rejected Avangrid's proposed 2021 acquisition of PNM Resources, saying the risks of the transaction outweighed the promised benefits to state ratepayers.

There was no clear timetable for the resolution of a judicial review of the refusal or other subsequent regulatory actions, Avangrid added.

Avangrid reaffirmed its 2023 forecast for earnings per share (EPS) and adjusted EPS, while PNM Resources said it would provide a financial update, including its preliminary results, in February.

The deal, worth $4.3 billion excluding debt, was unanimously approved by PNM's board in 2020 and was expected to create a renewables operator with a combined market value in excess of $20 billion.

"Although PNM Resources' board approved an extension, Avangrid did not accept it and terminated the merger," PNM Resources said in a separate statement.

(Reporting by Jyoti Narayan in Bengaluru; edited in Spanish by Benjamín Mejías Valencia)