BEIJING - Sales by China's largest 100 chain stores rose 5.1 percent year on year to 2.1 trillion yuan ($342.6 billion) last year, marking the slowest growth since 1998, according to a recent industry report.

The number of chain store outlets reached 107,000 in 2014, up 4.2 percent from the previous year, said the report of the China Chain Store and Franchise Association (CCFA).

Among the top 100 chain stores, department chain stores posted a sales increase of 2.7 percent year on year in 2014, while the sales growth for supermarket chain stores reached 6.5 percent, the CCFA said.

With e-commerce redirecting business from offline consumption to Internet platforms like Taobao.com, more chain store operators are going online, according to the CCFA.

Online sales for the top 100 chain stores increased five times year on year in 2014, but only contributed a little to their total sales, with 31.4 percent of the chain store giants earning less than 10 million yuan in online sales, according to the CCFA.

China's retail sales rose 10.6 percent year on year in the first three months this year to 7.07 trillion yuan, slowing from an annual 12 percent increase in 2014, data from the National Bureau of Statistics (NBS) showed.