Trucks, China drive GM to easily beat Street

General Motors delivered quarterly earnings that handily topped analysts' expectations on Wednesday, as strong demand for trucks in North America and improved profit margins in China overcame declining revenues.

After the earnings announcement, the company's shares rose more than 4 percent in premarket trading. (Get the latest quote here.)

The company posted third-quarter adjusted earnings of $1.50 per share, up from 97 cents a share in the year-earlier period.

Including $1.5 billion in costs for expenses related to the settlement of a Justice Department investigation of the automaker's mishandled ignition-switch recall, GM said net income for the latest quarter was 84 cents a share.

Read More There's a warning for investors in Ferrari's furore

Revenue totaled $38.8 billion for the quarter.

Analysts had expected the company to report earnings of $1.18 a share on $38.55 billion in revenue, according to a consensus estimate from Thomson Reuters.

The automaker reported North American profit margins of 11.8 percent for the third quarter, and forecast margins of at least 10 percent for the year.

General Motors Chief Financial Officer Chuck Stevens told CNBC strong truck and SUV sales, as well as the company's continued focus on driving cost efficiencies, drove the margin performance.

Asked whether a new contract with the United Autoworkers Union would pressure margins, Stevens said GM's labor costs are relatively small in the overall picture.

Read MoreGreat Scott! Lyft offering free DeLorean rides in NYC

"We are committed to sustaining 10-percent margins in North America over the next number of years, and to the extent that there's headwinds associated with the final resolution of the contract negotiations, we will work to offset those," he said during an interview on "Squawk Box."

Stevens said GM would also prioritize driving efficiencies in China, where it expects the market to grow 3 to 5 percent, but with greater levels of volatility.

"The results in the third quarter prove that our plan is working — half a billion dollars in equity income ... and 9.8 percent net margins."

Strong consumer demand, easy credit and generous incentives helped push auto industry sales up 15.8 percent year over year in September, according to Reuters. General Motors said it sold 251,310 cars and trucks during the month.

On Tuesday, GM announced a partnership with Korean electronics firm LG to develop the next generation Chevrolet Bolt electric vehicle.

Read MoreLG surges 14% on deal to make parts for Chevy Bolt EV

The Chevy Bolt EV, which can travel more than 200 miles on a single charge, will go into production late next year, the companies said.

LG will supply the car's infotainment system, battery pack, electric drive motor along with an array of other components and systems.

As of Tuesday afternoon, GM shares were down about 4 percent on the year, underperforming the S&P 500, which had declined about 1 percent this year.

—Reuters contributed to this report.