BEIJING, Sept. 20 -- Alibaba's historic IPO is more sad news for retailers in China, which continue losing shoppers as more Chinese chose to shop online.

Four of China's five largest retail groups lost customers in the 12-week period ending on Aug. 8 compared to a year ago, the latest snapshot data from UK-based market research company Kantar Worldpanel has shown.

The data also showed Chinese shoppers visited brick and mortar retailers less often than before.

Retailers Walmart, Vanguard, Carrefour and Bailian all had fewer shoppers than a year ago, suffering a decrease of 5.7 percent, 3.4 percent, 4.7 percent and 4.7 percent, respectively,

Only Sun Art Group managed to increase its shopper numbers by 1.7 percent year-on-year.

Though the value per basket is higher for all five retail groups, this increase does not offset the potential damage brought by fewer shoppers and fewer visits by shoppers.

In the 52 weeks up to June 13 of 2014, 32 percent of Chinese urban households purchased fast-moving consumer goods online, an increase of 44 percent from two years ago, according to Kantar Worldpanel China.