Wynne said she has confidence in new campaign co-chairs Health Minister Deb Matthews and Tim Murphy, an ex-MPP and chief of staff to former prime minister Paul Martin.
"And we will be very successful going forward," she said in London, Ont.
Ontario voters could be heading to the polls this spring unless one of the opposition parties supports the minority Liberals' budget. But the party won't have Sorbara, who guided the Liberals through three successful elections.
The former party president and finance minister said he's not being pushed out, but decided to step down in party to pursue a new "opportunity" that requires that he not perform any partisan duties. Sorbara wouldn't elaborate further.
It's time for a new team to take over, said Sorbara, 66.
"I'm getting old, and I don't have as much energy as I used to have," he said.
"I actually believe that this next election might not be for two-and-a-half years. I just didn't see me working as I had worked before for the next two-and-a-half years."
Sorbara resigned his seat in Vaughan last year, saying he wanted to focus his attention on the next campaign.
He was a key player in former premier Dalton McGuinty's government and was instrumental in launching a Liberal machine that's kept the party in power for almost a decade.
He helped revamp McGuinty's bland, bumbling image after the Liberals failed to defeat the Tories in 1999, using the same Chicago consulting firm that helped Barack Obama win the U.S. presidency.
The Liberals beat the Tories in 2003 and formed two successive majority governments before falling to minority territory in 2011.
His decision to help McGuinty after the 1999 election turned out into a "very intense" political career that lasted 14 years, Sorbara said.
"Not that I'm complaining about it, but I'm getting on," he said.
Sorbara's the latest member of the old guard to make an exit since Wynne took the helm.
Former finance minister Dwight Duncan and ex-energy minister Chris Bentley both resigned their seats last month.
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