As the world's biggest market for automobiles, China has been the most important contributor to automakers' global success.

The country helped propel General Motors in the fourth quarter, though the US company posted a weaker-than-expected profit on Thursday due to wider losses in Europe and rising costs in North America.

The results contributed to a third consecutive money-making year for GM, which is battling Germany's Volkswagen to retain its status as the best-selling foreign automaker in China.

The company said adjusted earnings before interest and taxes for international operations — mainly in China but also Russia, India and a few other countries — jumped 25 percent to $500 million in the quarter ended Dec 31.

For all of 2012, GM outsold Volkswagen in China, with record sales of its Wuling minivans. Deliveries at GM and its Chinese joint ventures rose 11 percent to a record 2.84 million vehicles. At Volkswagen, deliveries were up 24.5 percent to 2.81 million. In the fourth quarter, GM deliveries in China increased 15 percent to 754,000.

Although China's passenger vehicle sales growth slowed to 6.8 percent in 2012 from more than 30 percent two years before, the increasing demand for automobiles made the country the largest single market for both GM and Volkswagen.

Moreover, in 2012, GM and Volkswagen increased market share as Toyota, Honda and Nissan dealt with anti-Japanese sentiment tied to a territorial row with China. In 2013, with 95 auto brands continuing to fight for their share of China's market, vehicles sales in the country are expected to top 20 million for the first time.

GM and its Chinese partners captured 14.3 percent of the market in the latest quarter.

"China's been very critical for GM," said David Zoia, editorial director of WardsAuto, an industry information website. "During the 2009 downturn and bankruptcy, when things were at their worst in North America, China was carrying the ball for GM. The potential that is still there makes it even more critical to them."

Zoia pointed out that GM achieved its status as the top-selling foreign automaker in China despite entering the market after Volkswagen. He credited the US company's Chinese joint ventures, which accounted for 9.1 percent of international revenue in the fourth quarter, up from 8.4 percent, according to GM.