BEIJING, Dec. 4 (Xinhua) -- Overseas institutional investors are stepping up investment in China's inter-bank bond market as the country's financial opening-up widens, industrial data showed.

Their net purchase in the market stood at 98.8 billion yuan (about 13.98 billion U.S. dollars) in November, surging 96.42 percent month on month, according to the China Foreign Exchange Trade System.

By end-November, 2,517 overseas institutional investors had entered the country's inter-bank bond market. The total net purchase volume topped 970 billion yuan in the first 11 months of this year.

Chinese authorities announced new rules in October to make it easier for overseas institutional investors to invest in the interbank bond market.