BEIJING, Feb. 11 -- An index tracking the development of China's small and medium-sized enterprises (SMEs) edged up in January, data from an industry association showed Tuesday.

The SME development index rose by 0.1 points to 89.0, compared to the previous month, the China Association of Small and Medium Enterprises data showed.

Six of the eight sub-indices rallied in January, including market, labor and investment, according to the association.

In terms of sectors, sub-indices for the industry, transport, real estate, wholesale and retail sales, social service, and information transmission software sectors grew by 0.1, 0.4, 0.2, 0.2, 0.5 and 0.3 points, respectively.

In terms of regions, the sub-indices for the east, west and northeast regions stood at 89.7, 88.1 and 81.0, up 0.1, 0.3 and 0.3 points, respectively. The sub-index for the central region was 89.9, equivalent to the previous month.

In China, more than 90 percent of private companies are SMEs, and more than 90 percent of SMEs are private companies.