It also auctioned 10 billion yuan of 20-year bonds at a yield of 6.0 percent.

Reuters reported last month that the ministry planned to sell up to 100 billion yuan in bonds this year, braving the weak market after a deadly crash in July raised questions about the rapid growth of its high-speed network.

That will mark an increase from 80 billion yuan in corporate bonds it sold in 2010, and follows several issues of shorter-term debt earlier this year.

To make railway bonds more attractive, China's Ministry of Finance announced on Monday it would cut tax for companies on interest earned from bonds issued by the railway ministry between 2011 and 2013.