SHANGHAI--Chinese authorities fined Daimler AG's Mercedes-Benz 350 million yuan, or about $56 million, in the latest pushback against foreign auto makers in the world's largest car market.

The fine is small compared with Daimler's overall business in the country--last year Mercedes-Benz cars generated more in revenue on average from the broader Asia region in a single day. Still, it marks the increasing scrutiny foreign car makers and other global companies are facing in China as antimonopoly investigators step up their vigilance.

"Mercedes-Benz China accepts the decision and takes its responsibilities under competition law very seriously. We have taken all appropriate steps to ensure to fully comply with the law," a Daimler spokesman said.

Price regulators in the eastern Chinese province of Jiangsu said in a statement Thursday that they found Mercedes had colluded with its dealers on prices of E- and S-class cars as well as of some spare parts. Some Mercedes dealers in Jiangsu were fined a combined 7.9 million yuan, said the regulator, without specifying which dealers.

It said the fine against Mercedes was equivalent to 7% of its revenue in the province last year. Authorities in China can levy fines of as much as 10% of a company's sales for the preceding year.

The practices "excluded and limited market competition and hurt consumer interests," the regulator said in a statement.

The announcement on Thursday came after a broad investigation into foreign auto makers in China by antitrust officials last year, mainly for the way they sell spare parts and aftermarket services. State-run media has also accused many of the companies of making exorbitant profits from Chinese buyers. Many foreign luxury car makers cut the prices of cars, spare parts and aftermarket services last year.

In September, local price regulators in China levied a total of 280 million yuan in fines against Audi AG and Chrysler for allegedly overcharging Chinese consumers for cars and after-sales services. In August, the National Development and Reform Commission, China's top economic planner, slapped a 1.24 billion yuan combined fine against 10 Japanese auto-parts and bearings makers for antitrust activities.

In addition to foreign car makers, China has imposed fines on a variety of multinational companies ranging from pharmaceutical producers to eyeglass and contact-lens makers. In recent months, the authorities have been intensifying scrutiny over foreign technology companies.

Foreign companies have an overwhelming share of the luxury car market in China. Mercedes-Benz, BMW AG and Audi have a combined 72% of the market, according to an estimate by consulting firm Strategy&. China has become an increasingly important area for Daimler, accounting for about 10% of its revenue last year. Daimler's China revenue last year totaled EUR13.29 billion, up 24% from 2013.

Daimler doesn't break out its revenue from Mercedes-Benz cars in China. The Mercedes-Benz car brand in Asia generated EUR22.39 billion in revenue last year. China is the largest single market for the Mercedes-Benz brand in the region.

Rose Yu

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