BEIJING - A total of 240 small and medium-sized enterprises (SMEs) were added to China's New Third Board, marking a further expansion in China's over-the-counter market, after the board was officially established three years ago.

The move brings the number of companies listed on the New Third Board to 8,781 and represents China's effort to encourage the development of SMEs against the current downward economic pressure.

The market value of the 8,781 companies is about 3.36 trillion yuan ($about 509 billion).

Turnover on the New Third Board reached 2.68 billion yuan last week, a 19.27 percent decrease on the previous week.

The New Third Board, or National Equities Exchange and Quotation (NEEQ) system, serves as a national share transfer system for SMEs to transfer shares and raise funds.

It was initiated in 2006 as an experimental platform to facilitate financing for China's non-listed small and promising high-tech enterprises in Beijing's Zhongguancun Science Park.

The present system was officially established on Jan. 16, 2013 after years of trials in cities including Shanghai, Wuhan and Tianjin.

It complements the existing stock exchange, the SME board and the ChiNext board, being seen as an easy financing channel with low costs, simple listing procedures, and a short application period for companies not qualified for listing on the major exchanges.