Unifor announced a tentative contract agreement early Tuesday with General Motors of Canada just after a midnight strike deadline.

"It wasn't the threat of a deadline that forced a decision, I think it was understanding Canada is one heck of a place to do business," said Unifor president Jerry Dias. "We build the most quality vehicles in the world and we run very profitable facilities as well."

Dias said he was thrilled to announce the agreement, but called it a "difficult set of negotiations."

The union's committee is unanimously recommending the deal. Ratification votes are set for Sunday in Ontario at the Oshawa and St. Catharines plants as well as the parts distribution centre in Woodstock.

A major concession in the talks was an agreement by the union to convert all new employees to a defined contribution pension plan. That's different from the defined benefit plans that legacy employees all have.

"We knew that over the life of the last four-year collective agreement GM did not hire one person, and a lot of it had to do with their public position on the defined benefit pension plan," Dias said Tuesday in an interview with Matt Galloway, host of CBC Toronto's Metro Morning.

"Was it worth it to get new employees the opportunity to get jobs at our wages, at our security level and give up the [defined benefit] plan for new starts? The answer is yes," Dias said.

He also said GM's contribution to the new defined contribution plan will be more than some companies are putting into hybrid plans. "GM is not getting out of this on the easy, I can assure you."

In the previous contract, Unifor made a concession to move to a hybrid contribution-benefit system, but a year later struck a deal for GM workers in Ingersoll, Ont. — who operate under a separate bargaining schedule — which entailed a defined contribution plan.

A key sticking point in the negotiations was the union's request to secure more work for the 4,000 GM employees it represents in Ontario.

Dias said earlier Tuesday that assurances for the job security of employees in Oshawa and St. Catharines were achieved through "hundreds of millions of dollars of investment for our Canadian facilities."

Dias said a result of the investment, Oshawa would be the only GM plant in North America to have the ability to build both cars and trucks.

GM seeks government support

The consolidated line in Oshawa will continue its existing commitment into 2017 for the Chevy Equinox SUV, but no more. The flex line — which handles the Buick Regal, Chevrolet Impala and Cadillac XTS but had no products scheduled past 2019 — has now received a yet-to-be-named commitment from GM beyond that date.

"Are we going to end up with a different product in Oshawa? The answer is yes," said Dias, adding that as a result the plant would be "hiring in the long term and the short term."

Yhe union's committee is unanimously recommending the deal. Ratification votes are set for Sunday in Ontario at the Oshawa and St. Catharines plants as well as the parts distribution centre in Woodstock. (Chris Young/Canadian Press)

For St. Catharines, he hailed a rare migration of product from Mexico to Canada. Additional volume related to the company's engine program will head to the southern Ontario city's shop.

"Heaven only knows we've seen enough of it go the other way around," said Dias.

GM in a statement early Tuesday said the deal would "enable significant new product, technology and process investments" at the two Ontario plants, adding "we will be working with government on potential support."

The four-year contracts with GM, Ford and FCA — the corporate parent of the Chrysler line — were set to expire at midnight. Unifor identified GM as the target for its talks, in the hopes that any agreement there could be used as a benchmark with other automakers.

Dias admitted a "negative change" to get the current deal struck was that new GM hires would be under a defined contribution plan, which would have widespread ramifications given the pattern bargaining within the auto industry.

The Unifor president said while the broad framework was achieved, the two sides would be returning to the table to iron out specific language. Without getting into specifics, Dias said wage progressions would change and wage increases were secured that he deemed "fair for the economic times."

Dias praised GM for its "willingness to find a solution."