Michael Bryant, front, is shown with Ontario Premier Dalton McGuinty at a September 2008 news conference after his appointment as minister of economic development. (Nathan Denette/Canadian Press)

Ontario Economic Development Minister Michael Bryant will step down from his cabinet post Monday to head a new corporation aimed at attracting investment to Toronto.

Bryant, 43, will become president and CEO of Invest Toronto, an economic development agency whose mission is to develop the city's extensive real estate holdings and promote investment through marketing and trade missions.

Liberal Premier Dalton McGuinty said Saturday that Bryant had advised him of his decision a day earlier. He also plans to resign as MPP.

Bryant has been Ontario's point man in the provincial and federal government talks with General Motors and Chyrsler Canada, which have sought billions in government aid.

News of his departure comes as General Motors heads into a crucial week of last-minute dealmaking to qualify for government loans. The company has until May 31 to present its restructuring plans to stave off financial collapse.

McGuinty, who has also been involved in the auto talks, will take over Bryant's portfolio temporarily.

Lauded by premier

"Michael has always tackled each new role with his trademark enthusiasm, intelligence and energy," McGuinty said in a statement.

"I know Michael will bring the same level of passion, insight and commitment to his new role with Invest Toronto that he has brought to the provincial government," he said.

"I'm excited to begin new duties with Invest Toronto after resigning as MPP for St. Paul's in the coming weeks," Bryant said in a release Saturday.

"I'm honoured to have served the people of St. Paul's under the incredible leadership of the premier for the past 10 years. I look forward to an announcement with Mayor David Miller about my future plans with Invest Toronto on Monday."

Bryant had long been considered a top contender to succeed McGuinty, despite his sometimes frosty relations with the premier.

His brash, attention-getting style didn't always go over well with his boss, and news of his hasty departure from cabinet immediately raised questions about whether the relationship had permanently soured.

Bryant raised eyebrows earlier this month when he trumpeted his vision for a stronger government role in business, a so-called "reverse Reaganism" plan that would have Ontario picking "winners and losers" on a case-by-case basis.

A few days later, McGuinty tried to temper those remarks, saying he was leery of picking specific companies to support.