The State Administration for Market Regulation imposed fines on 28 companies for not declaring the concentration of business operators as per the Anti-monopoly Law, according to the regulator on Sunday.

The market body said the companies did not declare the concentration of business operators, a practice through which one company obtains control over another which may lead to monopoly, but all these cases were "past transactions".

Tencent Holdings Ltd was fined a total of 6 million yuan ($896,245) over 12 acquisitions on companies, including retailing firm Okaybuy (China) Holding Inc and DeepBlue Alpha Inc. Alibaba's subsidiaries were fined 2.5 million yuan for not reporting five deals, including the acquisition of logistics firm Best Logistics.

"With the anti-monopoly supervision being normalized, the awareness of business operators has continuously improved. Companies have actively self-examined past transactions and reported them to authorities," the market regulator said.

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