Two Japanese automotive bearings makers said on Tuesday a Chinese regulator has ordered them to pay fines for violating antitrust laws as Beijing intensifies its scrutiny of business practices in the auto sector.

Earlier this month, the National Development and Reform Commission (NDRC) said the government had completed investigations into 12 Japanese auto parts makers and was preparing to hand out punishment according to the law. Sectors from autos to pharmaceuticals have come under the spotlight as China seeks to tighten compliance with anti-monopoly laws.

NSK Ltd (6471.T) said the regulator issued a 174.9 million yuan ($28.5 million) fine over unspecified violations of the China's antitrust law. Rival NTN Corp (6472.T) also said the Chinese regulator ordered it to pay a 119.2 million yuan fine.

"NSK and its subsidiaries...have taken and will continue to take comprehensive measures with the help of outside experts and others to ensure strict compliance with all applicable laws and regulations," the Tokyo-based company said in a statement.

NTN said it would conduct its business while adhering to principles of fair and honest competition.

Both companies said should any revisions be made to their profit forecasts for the financial year to March 2015, they would be announced swiftly. The fines are small compared to the companies' overall sales: for that 12-month period, NSK is forecasting it will book revenue of 926 billion yen ($9 billion), while NTN expects revenue of 660 billion.

Separately, Yazaki Corp, a Japanese maker of wiring harnesses, said it has received a notification from the NDRC and that it would disclose details on Wednesday. "We are currently closely studying the content (of the notification)," spokesman Daichi Saito said.

Denso Corp (6902.T), the world's second-biggest automotive parts maker, declined to comment in detail. "We will wait for an announcement by the authorities and once that is made, we will comment," Denso spokesman Sadayoshi Yokoyama said.

($1 = 6.1406 Chinese yuan)

($1 = 102.6600 Japanese yen)

(Reporting by Yoko Kubota; Editing by Chris Gallagher and Kenneth Maxwell)