In contrast, a2 Milk has said it has had no impact from the new Chinese e-commerce laws that came into effect in January.
The company does not report quaterly, but it said early this month that it was making "pleasing progress" for Chinese label and English label cross border e-commerce channels.
Investment bank UBS, in a comprehensive report on the China's infant formula sector, said a2 Milk looked to be gaining market share at the expense of its bigger competitors.
Beingmate improving
In its report, UBS said data pointed to a stronger first half performance from China's Beingmate. Beingmate is 18.8 per cent owned by Fonterra but the co-op has the investment under review.
The investment bank said Beingmate's share of online best sellers recovered back towards levels reported 12 months ago.
"At the same time, we have seen a sequential lift in online median price for Beingmate. However, it is too early to suggest that Beingmate online market share is sustantialby improving." Beingmate's share price has doubled over the last six months to 8 yuan.