BEIJING, Feb. 15 -- The People's Bank of China, the central bank, said Saturday the country had issued 5.1 trillion yuan ($773.3 billion) worth of bonds in 2010, an increase of 3.1 percent over that in 2009.

National debt, debt issued by policy banks and short-term financing bonds contributed mainly to the bond market expansion last year, said a central bank statement posted online.

The central bank also noted that the total value of bonds in China's inter-bank market soared 21.5 percent year-on-year to 15.8 trillion yuan at the end of 2010.

In 2010, the Ministry of Finance issued 1.7 trillion yuan of bonds via the inter-bank market.

Currently, China's inter-bank issuers include the Ministry of Finance, policy banks, Ministry of Railways, commercial banks and other financial institutions.