The Rothsay business operates six rendering plants and a biodiesel plant employing a total of 550 people in four provinces.
The rendering plants in Manitoba, Ontario, Nova Scotia and Quebec recover fats and proteins produced as a byproduct of the slaughtering process.
The biodiesel plant in Quebec creates products for use as fuel.
Maple Leaf says the Rothsay employees will transfer to the new owner, Darling International Inc. of Irving, Texas.
Toronto-based Maple Leaf will receive about $645 million for Rothsay and use the money to pay down corporate debt.
On the Toronto Stock Exchange, Maple Leaf shares closed up $1.05, or 7.84 per cent, at $14.44.
"The sale of our rendering and biodiesel business supports our strategy to focus on effective capital deployment and profitable growth in the consumer packaged foods market," said Michael McCain, president and CEO.
"We are delighted to have concluded almost a year-long process with an agreement with Darling, the North American leader in food waste recycling."
Randall Stuewe, chairman and CEO of Darling International, said: "We look forward to joining forces with Rothsay's management team and employees and to the opportunity this brings our shareholders for future growth."
Maple Leaf Foods is a meat and bakery company which employs some 19,500 people at its operations across Canada and in the United States, the United Kingdom and Asia. It had sales of $4.9 billion in 2012.