General Motors (GM) said Friday that it will return to a two-shift operation at its assembly plant in Oshawa, Canada, "in light of forecasted demand and the evolving trade environment."

The company also said it is reorienting its Oshawa plant "to build more trucks in Canada for Canadian customers."

Unifor, a Canadian labor union representing GM workers at the plant, said the company plans to reduce the number of work shifts to two from three in the fall. Following the announcement, the union called on the Canadian government to "immediately review and reconsider" GM's tariff-exempt status in Canada.

"Cutting the third shift at Oshawa Assembly is a reckless decision that deals a direct blow to our members and threatens to ripple through the entire auto parts supplier network," said Unifor National President Lana Payne. "GM needs to reverse this short-sighted move before more damage is done."

Shares of GM were up 1.2% in early trading Friday.

Price: 45.59, Change: +0.54, Percent Change: +1.19