China's market regulator on Saturday said it was fining companies including Alibaba, Baidu, and JD.com for failing to declare 43 deals that date as far back as 2012 to authorities, saying that they violated antitrust legislation, Reuters reported.

Enterprises involved in the cases would be fined 500,000 yuan ($78,000) each, it said, the maximum under China's 2008 Anti-Monopoly Law.

China has been tightening its grip on internet platforms, reversing a once laissez-faire approach, and citing the risk of abusing market power to stifle competition, misuse of consumers’ data, and violation of consumer rights.

The deals, however, did not have the effect of eliminating or restricting competition, the regulator said.

In December last year, it fined Alibaba, Tencent-backed China Literature, and Shenzhen Hive Box 500,000 yuan each for not reporting past deals properly for antitrust reviews, the first time it had ever done so.

($1 = 6.3863 Chinese yuan renminbi)