One year after winning his third mandate, McGuinty called a meeting of his caucus and, with his wife Terri in attendance, said he will step down as premier, though he will retain his seat in the Legislature, The Globe and Mail reported.
"It's time for renewal," McGuinty said. "It's time for the next Liberal premier, it's time for the next set of Liberal ideas to guide our province forward."
He has been leader of the Liberals for 16 years and will stay in that position until his successor is selected, the Toronto newspaper said.
The move comes amid accusations from the opposition that Cabinet members misled the Legislature by not releasing documents relating to the cancellation of two power plants.