CAW president Ken Lewenza listens to a reporter's question during a news conference Friday in Toronto. (Chris Young/Canadian Press)

General Motors Canada and the Canadian Auto Workers union have reached a new deal on labour concessions.

The two sides reached the deal after days of slow negotiating, CAW president Ken Lewenza confirmed during a news conference in Toronto Friday morning.

Lewenza said the union and the automaker reached the tentative deal around 11 p.m. ET Thursday.

Voting on the agreement by union members is slated for Sunday and Monday.

"We have preserved our wages. We have preserved and secured our pension benefits," said Lewenza. "We have protected most of our core benefits."

He said the deal meets the competitive benchmarks laid out by governments, and guarantees that company plants in the Ontario communities of Oshawa, St. Catharines and Woodstock will remain open.

The union said the agreement will lower GM's hourly labour costs by $15 to $16 per hour. That is in addition to the $7 per hour in cuts reached through a labour deal between the company and the union in March.

Union members will forego a $3,500 lump-sum payment to each worker for lost vacation time. That money, said Lewenza, is expected to be funnelled toward the pension fund.

Speaking to reporters in Calgary, Prime Minister Stephen Harper said he was glad General Motors Canada and the CAW had reached an agreement.

"I’m hopeful when we look at the deal that all involved have made the difficult decisions necessary to create a viable company," Harper said.

Pension issues were one of the major items, with Lewenza saying Friday that the union has agreed to a pension benefit freeze extending through 2015.

Key requirement

He pointed out that the pension plan for the workers is only 39 per cent funded on a windup basis

Union pension official Sym Gill said the pension shortfall is roughly $6.5 billion to $7 billion, adding that the pension is expected to be back on a fully funded basis in 10 years.

A GM Canada spokesman declined to comment on the agreement, pending the ratification vote.

A money-saving deal between the automaker and the union is a key requirement of GM Canada getting financial backing from the governments of Canada and Ontario.

The tentative deal came just a day after General Motors reached an agreement with the United Auto Workers, a development that seemed to spur both sides in the Canadian negotiations.

"The reality is this: we’re not dealing in a normal situation here. The government of the U.S. has made a decision … it will engage in politically driven restructuring of GM," Harper told reporters in Calgary.

"Either we participate or these companies — which are big in the economy — will simply be restructured out of Canada. That's not a reasonable alternative. We are committed to participating," he said.

"It will be a very expensive proposition. Not doing anything would be more expensive, more damaging."

Lewenza said he expects GM will file for bankruptcy protection in the United States, although he was unsure if GM Canada will file for court-ordered creditor protection here.

He said the new labour agreement is protected even if the company files for protection under the Companies' Creditors Arrangement Act (CCAA).