Updated

The Canadian government and Ontario province have sold off a large part of their share in General Motors, four years after joining a US bailout of the auto giant.

The two placed 30 million shares, about one-fifth of their stake in GM, in a block trade with Bank of America Merrill Lynch and RBC Capital Markets, the Canadian Department of Finance announced late Tuesday.

At Monday's market closing price the deal could be worth $1.1 billion.

It left the Canada GEN Investment Corporation, which holds the shares on behalf of Ontario and the federal government, with 110 million shares of GM common stock.

"This decision is another step forward in returning GM to private sector ownership and supporting its continued contribution to the Canadian economy," the department said in a statement.

Canadian authorities took part in the 2009 US bailout of GM, which plunged into insolvency during the financial crisis, with authorities anxious to protect tens of thousands of jobs in auto plants inside Canada.

"In the worst of the global recession, we took the necessary action to protect Canadian jobs and communities with a coordinated investment in GM and Chrysler, along with the Ontario and US governments," said Finance Minister Jim Flaherty in a statement.

"The value of this investment can be seen in the jobs and companies saved and tax bases preserved."