Texas' power grid operator has fired its president and CEO following last month's winter storm that left millions without electricity, media reports said.

Electric Reliability Council of Texas (ERCOT) has under come fire from customers and politicians over its apparent failure to prepare for the cold weather and the enormous bills some customers have faced due to a massive spike in energy prices.

President and CEO Bill Magness was fired late Wednesday after the ERCOT board held an emergency meeting and gave him 60 days' termination notice, CNN and other media reports said, citing an ERCOT statement.

Texas Lieutenant Governor Dan Patrick, who has called on the leaders of ERCOT and the Public Utility Commission of Texas to resign, welcomed the news.

Millions of Texans were left without power in mid-February as Arctic conditions overwhelmed local utility companies ill-prepared for such weather
Millions of Texans were left without power in mid-February as Arctic conditions overwhelmed local utility companies ill-prepared for such weather AFP / Thomas Shea

"2 days ago, I called on ERCOT and PUC leaders to resign. Good news -- now they are both gone," Patrick tweeted.

"Next --- one of my top 31 priorities --- reforming ERCOT and fixing what went wrong."

Several board members of ERCOT have already resigned after millions of Texans were left without power in mid-February as freezing conditions overwhelmed local utility companies ill-prepared for such weather.

PUC chairwoman DeAnn Walker resigned on Monday.

Texas governor Greg Abbott has ordered an investigation into the grid operator, and the Federal Energy Regulatory Commission has also said it will probe the factors behind the power outages.