Michael Hervey, chief operating officer and acting CEO of LIPA, will step down at the end of the year, the utility said in a statement Tuesday evening.
Hervey has come under fire from Gov. Andrew Cuomo, who last week accused LIPA of being unprepared for the storm and slow to respond to the massive power outages that followed.
"They failed and they should be held accountable for their failure," Cuomo said at a press briefing in his Midtown office last Thursday.
Cuomo said there was "a management issue" at LIPA and he called for "a ground-up redesign."
LIPA Chairman Howard Steinberg did not mention the storm in his brief statement on Hervey's departure but said he accepted Hervey's resignation "with regret."
Hervey told the Wall Street Journal he had planned to step down even before the storm.
LIPA, which provides power to Long Island and the Rockaways, still had more than 6,500 customers without electricity as of Tuesday evening, according to its website.
That included just 138 customers in the Rockaways — but there were also still an additional 24,500 customers there that needed to have electrical equipment repaired before they could receive the electricity LIPA had restored, the utility said.