New York (CNN Business) The six-week strike at General Motors will end up costing the automaker about $2.9 billion, the company said Tuesday.

Nearly 50,000 hourly GM workers went on strike starting September 16 , two weeks before the end of the quarter. It ended on Saturday, October 26.

GM lost money because factories in the United States, as well as some in Canada and Mexico, were idled during the walkout. The strike directly affected 31 GM factories and 21 other facilities, spread across nine states, mostly in the center of the country.

The strike's cost in the final two weeks of the third quarter came to just under $750 million. GM will account for the rest of the loss this quarter, as it estimates the total loss will come to about $2 per share, the company said Tuesday.

GM was able to post a $2.3 billion profit in the third quarter, despite the strike and a $318 million drop in sales. The revenue from North American vehicle sales actually increased $321 million in the period as US sales rose 6%. International sales, which ironically had little impact from the strike, took a hit. The market for new car sales in China, GM's largest market, has slowed considerably in the last year, cutting GM's sales there by 16%, as it lost market share in that key market.

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