(Yicai Global) May 11 -- Meituan and Pinduoduo, two of China’s biggest internet companies, promised to make changes after their stocks plunged in the wake of criticism from a prominent consumer watchdog group.

Pinduoduo and Meituan vowed improvements after the Shanghai Consumer Council flagged up problems at the group-buying titan and food delivery giant. The pair, which were pulled in for face-to-face meetings on the same day, will quickly submit rectification reports to the watchdog, they said in separate statements yesterday.

Pinduoduo [NASDAQ: PDD] closed 9.1 percent lower at USD121.60 in New York yesterday, after sinking as much as 13 percent to USD116.22, the lowest since November. In Hong Kong today, Meituan [HKG: 3690] slid up to 8.7 percent to HKD240 (USD30.90), its lowest since September. The shares ended down 5.3 percent at HKD249.

The main issues at Pinduoduo involved the quality of goods, counterfeiting and infringement, forced order cancellations, fraudulent deliveries, after-sales service, and gaining new users through bargaining activities, the Shanghai Consumer Council said in a statement posted on its WeChat account.

Shanghai-based Pinduoduo needs to enhance vendor qualification controls, ban counterfeit products, deal with consumer complaints more quickly, and attract new clients in a fair manner, the SHCC said.

It said Meituan should improve its product descriptions and service terms while refraining from relying on its dominant market position. The Beijing-based firm must deliver orders in a timely manner and actively engage with consumers when problems arise, the council added.

The SHCC plans to summon other internet platforms to discuss similar issues, it said. Such platforms should give up on thinking that popularity and influence are what matter the most and pay attention to protecting consumers’ rights and interests instead, it added.

Editor: Emmi Laine, Xiao Yi