The Chinese unit of General Motors has been fined 201 million yuan ($28.9 million) for infringing on the rights of consumers and its competitors through price-fixing since 2014, the National Development and Reform Commission, China's top economic regulator, said on Friday.

The amount was about 4 percent of SAIC GM's sales in China last year. It was also the second time a US company was fined this month as the nation strengthens anti-monopoly regulation.

Earlier this month, the commission imposed a fine of 119 million yuan on the China unit of US company Medtronic, a leading supplier of high-end medical devices, for price-fixing.