Texas' power grid operator ousted chief executive Bill Magness on Wednesday, as the fallout continues from a deadly blackout last month that left residents without heat, power, or water for days.

His departure followed fierce criticism by state lawmakers of the handling of the crisis by the Electric Reliability Council of Texas (ERCOT), which has led one large electricity provider to seek bankruptcy and put several others near to it.

The mid-February storm temporarily knocked out up to half the state's generating plants, triggering outages that killed dozens and pushed power prices to 10 times the normal rate.

"ERCOT's decision to oust CEO Bill Magness signals accountability for the disaster that swept through our state two weeks ago," Texas Attorney General Ken Paxton said in a statement on Twitter.

"(This step) offers the opportunity for new leadership that can more efficiently prepare and direct our state's resources when dangerous weather strikes," he added.

Texas Lieutenant Governor Dan Patrick, who earlier this week called for the heads of ERCOT and the Public Utility Commission to resign, also welcomed the move.

The legislature now can begin "fixing what went wrong," Patrick said.

ERCOT said in a statement cited by multiple media organizations that its board had directed that Magness be given a 60 days' termination notice. The board would begin an immediate search for a new CEO.

Magness worked at ERCOT for more than a decade and became its CEO and president in 2016 after working as its general counsel, the Texas Tribune newspaper reported.

Brad Jones, former head of New York's power grid, is the leading candidate to replace Magness as ERCOT's CEO, Bloomberg reported, citing people familiar with the board's thinking.

Magness was grilled for hours last week for leaving power prices at up to 450 times the usual rate after the threat to the state's grid had ended.

Seven of ERCOT's 15 directors have resigned in the last week and the head of the state's Public Utility Commission, which supervised ERCOT, resigned on Monday.

The winter storm caused widespread blackouts across Texas, a state unaccustomed to extreme cold, knocking out power to more than 4 million people at its peak.