(Yicai Global) Dec. 24 -- China's Alibaba Group said today that its business operations remain normal after the country's top market regulator started an investigation into the e-commerce giant's alleged unfair market practices.

"Alibaba will actively cooperate with the regulators on the investigation," the Hangzhou-based firm said in a statement today after receiving a notice about the anti-monopoly probe the same day.

Shares of Alibaba [HK:9988] plunged as much as 8.8 percent to HKD226.60 (USD34.60) by 11.30 a.m., the lowest since early July. Alibaba Health Information Technology [HK:0241] dropped over 10 percent.

Editor: Emmi Laine