General Motors

(GM) - Get Report

shares slipped Friday after the automaker said a three-month strike by the United Auto Workers at

American Axle & Manufacturing Holdings

(AXL) - Get Report

significantly hurt its production in the second quarter.

On Thursday, the UAW said it had ratified a new labor agreement with auto components and systems maker American Axle. The strike began in February, when about 3,650 employees represented by the UAW went on strike at the plants in New York and Michigan.

GM disclosed Friday that the strike resulted in lost production of 230,000 vehicles, an impact of roughly $1.8 billion on second-quarter pretax earnings. In a regulatory filing, GM said the work stoppage had affected approximately 30 plants in North America. In the first quarter, GM said the strike resulted in a loss of 100,000 production units, which had an estimated impact on earnings before tax of approximately $800 million

"We anticipate only a portion of this lost production will be recovered, due to the current economic environment in the United States and to the market shift away from the types of vehicles that were impacted by the action at American Axle," GM said in the filing. Shares of the automaker were recently down 60 cents, or 3.3%, to $17.83.

In American Axle's first-quarter earnings report, the company said production volumes for the full-size truck and SUV programs for GM and Chrysler were down approximately 31% in the quarter as compared to the prior year.

Additionally, GM said it would offer $215 million to American Axle to fund employee buyouts and early retirements, which is $15 million more than the automaker originally said it would provide.

Shares of American Axle were falling 44 cents, or 2.3%, to $18.81. Among other auto parts makers,

Lear

(LEA) - Get Report

was off 1.8%,

Visteon

(VC) - Get Report

was down 1.9%,

ArvinMeritor

( ARM) slid 3.1% and

Dana Holding

(DAN) - Get Report

was falling 2.8%.

The news comes a day after GM rival

Ford

(F) - Get Report

said it will increase production of smaller, hotter-selling vehicles while cutting back on gas-guzzling SUVs and large trucks as consumers "move quickly" to more fuel-efficient vehicles. The company also said it would cut overall production of vehicles for the rest of the year, which will impact its earlier forecast of returning to the black in 2009.

After falling 8.2% during Thursday's session, shares of Ford were down another 4.3% to $6.85 on Friday.