Having done business in China for more than 16 years, Metro China has gradually realized that significant synergies can be generated from the retailing sector. Hoelzer said that its retailing business can contribute almost 50 percent to Metro's China sales.

"Both (B2B and B2C) businesses bring us a lot of synergies. We could not survive without any one of them," said Hoelzer.

"The sales revenue generated from the retail business might be the main driver for the company to seek rapid expansion in China," said Peng Jianzhen, deputy secretary-general of China Chain Store & Franchise Association.

In addition, experts said opening 12 stores in one year is not that uncommon in the fast-growing Chinese market.

"Metro's expansion in China was not fast in the past decade compared to many international giants, so opening 12 stores is quite normal," said Peng.

Metro has 63 stores in 45 cities across the country. In contrast, Walmart has opened more than 260 stores in China since 1996.