Weakness in Asia leads to profit drop: GM
But the slowing economy could hurt automakers in China, including GM. The nation's GDP growth fell to 7.5 percent in the second quarter, pointing to a further slowdown in the world's second-largest economy.
A marketing executive with South Korea's Hyundai Motor Co, who asked to remain anonymous, told Reuters he expects second-half China sales to slow because of the weakening economy.
The South Korean vehicle group's sales in China surged 32.6 percent in the first half in China to 787,308 units.
Meanwhile, Japan's Nissan Motor Co, which reported stronger profits on Thursday, said it saw "positive signs of improving sales volume in China" as it narrowed its sales drop in the country.
In the first half, Japanese brands saw a sales recovery in China as their year-on-year sales decline narrowed each month. Nonetheless, their combined market share still fell by 4.2 percentage points from a year earlier, data from the China Association of Automobile Manufacturers show.
The latest quarter saw GM continue to grow in China, where its sales have exceeded the number of vehicles it sells in the US, its second-quarter market share declined.
GM had 13.9 percent of the market in the latest quarter, down from 15.1 percent in the first quarter and flat with the same period a year earlier.
Although operating earnings in China increased, Chief Financial Officer Dan Ammann said pricing pressure in Australia and Southeast Asia and costs in India caused international earnings to plunge 64 percent.
Revenue from joint ventures in China rose 9.4 percent, less than the 11.7 percent gain of the first quarter but up from the 9.3 percent rise of last year's second quarter.
Deliveries in China came to 751,000, down from 816,000 in the first quarter but up from 672,000 in the second quarter of 2012.
In the first half, China's passenger vehicle sales rose 13.8 percent to 8.67 million units.