The Canadian Auto Workers union appears prepared to make a key concession in contract negotiations with the three big U.S. automakers if they offer an acceptable tradeoff.

The Globe and Mail reported in its online edition Thursday that the CAW has laid out a proposal to cut wages for new employees at the Canadian operations of General Motors, Ford Motor and Chrysler.

CAW president Ken Lewenza couldn't be reached for comment early Thursday, but a union official says there's been an offer to ease up on wages for new employees in exchange for a commitment to new investments at the Canadian operations.

The Globe report says the union is also prepared to extend the time frame on a current "two-tier" system of paying new employees at a lower scale for several years.

The union prefers to describe its offer as a willingness to extend its proposal as a "multi-year wage progression" -- something already in the contracts that end early next week.

The Globe report says the CAW is proposing to start newly hired workers at lower wages for the first 10 years of their employment at the three big North American automakers -- four more years than under the current system.

Lewenza has said the union opposes a permanent two-tier system — such as one accepted by the United Auto Workers union for employees at the automakers' U.S. plants.

He has also said it's vital for Ford, GM and Chrysler to include commitments that would ensure the economic viability of their factories in Ontario.

However, the three U.S. automakers have said they need to lower their costs in Canada in the next multi-year labour agreement with the union.

The union and the three automakers formally kicked off negotiations for new three-year contracts a month ago. They're working toward a deadline of 11:59 p.m. on Sept. 17.