Walmart Inc. opened its first store in China in 1996, a sprawling supercenter in the Hong Kong border city of Shenzhen. It has been working to find the right strategy ever since.

Walmart has grown in China, but slower than competitors. Its giant hypermarkets, which it originally hoped would enable it to become a retail leader in China, have struggled for years to keep pace with Chinese retailers, known for their array of local products and more recently for fast home deliveries.