Sales by China's largest chain stores rose 9.9 percent to 2.04 trillion yuan (329 billion US dollars) last year, marking the slowest growth since 1998, according to a recent report by the China Chain Store and Franchise Association (CCFA).

It was the first time the country's largest chain store operators reported single-digit growth in sales since the CCFA began compiling the top-100 chain store list in 1998.

Sales by the largest chain store companies, including Suning Commerce Group Co., Ltd. and Wal-Mart China, accounted for about 8.6 percent of China's total retail consumption of goods and services, the report released in late April showed.

Among the chain store giants, 21 retail companies cut their number of outlets last year amid rising costs, while 15 of them posted declines in sales, the CCFA said.

The newly opened outlets of the 45 largest convenience stores expanded by 9.5 percent in 2013, compared with a mere 0.4-percent increase in new outlets of 50 big department stores and supermarkets.

As e-commerce has wooed offline consumption to Internet platforms like Taobao.com, more chain store operators are going online, according to the CCFA.

Out of 100 chain store retail giants, 67 companies have opened their own online businesses, which contributed only 3.7 percent to their total sales, according to the CCFA.