General Motors Co. is preparing to pay the bill for a nearly six-week long strike at its U.S. plants by slashing its earnings forecast for the year by US$2 a share.

The walkout hit GM’s profit by US$1 billion in the third quarter alone, forcing the automaker to lower its 2019 adjusted earnings per share estimate to a range of US$4.50 to US$4.80, down from an earlier projection of US$6.50 to US$7 a share.

GM said the strike will cost the automaker about US$2.9 billion in lost earnings this year, some of which will hit fourth quarter earnings; on a basis of earnings before interest and taxes, the impact would reach US$3.8 billion to US$4 billion. The Detroit-based company may be able to make up for some lost vehicle output as it ramps up production now that it has settled a new four-year labor deal. The labour action started on Sept. 16 at the tail end of the quarter, denting earnings by 52 cents US a share.

GM also repriced its stakes in Lyft Inc. and French carmaker Peugeot SA, which lowered profit by another 15 cents US a share. GM owns 6.7 per cent of Lyft and has warrants in Peugeot.

Still, GM’s adjusted per share profit for the quarter — which adds back losses from the strike and other one-time charges — beat Wall Street expectations of US$1.29 a share with US$1.72.

“Our underlying third-quarter performance demonstrates the ongoing resilience and earnings power of our company,” GM Chief Financial Officer Dhivya Suryadevara said in a statement.

For GM, the strike’s impact is two-fold. The walkout not only hit profits for this year but also adds $100 million a year to its labour costs going forward, according to an estimate from Credit Suisse.

Shares of the automaker are up 9.5 per cent so far this year, but down 5.7 per cent since just before the strike started.

As part of the new labor deal, GM will give workers a three-per-cent raise, US$11,000 ratification bonuses for tenured workers and reduce the amount of time entry-level workers need to get to top pay. The deal also sets some limits on the numbers of temporary workers who can be hired.